DTC Descriptions

Name Of Code: P0613 (11, 13, 45, 94) - Internal Controller

When Monitored: Whenever the key is in the Run or Run/Start position.

Set Condition: This code is set whenever Powertrain Control Module (PCM) senses an internal error.

Theory Of Operation: The PCM is constantly monitoring it's internal processor. If an internal problem is detected, this DTC will be set. This DTC can also be set by a bad ground to the PCM and/or Trans Control Relay.

Transmission Effects: The MIL will illuminate (this DTC can take up to five minutes of problem identification before illuminating the MIL) and the transmission system will default to the Immediate Shutdown routine.

Possible Causes:

PCM ground circuit.
Relay ground circuit.
PCM

Name Of Code: P1684 (12) - Battery Was Disconnected (Informational Code Only)

When Monitored: Whenever the key is in the Run/Start position.

Set Condition: This code is set whenever the PCM is disconnected from battery power (B+) or ground. It will also be set during the DRBIII® Battery Disconnect procedure.

Theory Of Operation: A battery backed RAM (Random Access Memory) is used to maintain some learned values. When the battery B(+) is disconnected, the memory is lost. When the B(+) is restored, this memory loss is detected by the PCM. The code is set and the learned values are initialized to known constants or previously learned values from EEPROM (Electronic Erasable Programmable Read Only Memory). This results in the initialization of some parameters.

Transmission Effects: Loss of trouble code data Immediate Limp-in mode if power is lost while operating the vehicle. Normal operation is resumed if the power is restored during the same key start.

Possible Causes:

Battery voltage removed from PCM
PCM disconnected
Dead Battery
Low battery voltage during cranking
Battery Disconnect by DRBIII® or MDS
Bad PCM ground circuit.

Name Of Code: P0891(14) - Transmission Relay Always On

When Monitored: Ignition key is turned from off position to run position and/or ignition key is turned from crank position to run position.

Set Condition: This code is set if the PCM senses greater than 3 volts at the Trans Relay Output (switched battery) terminal of the PCM prior to the PCM energizing the relay.

Theory Of Operation: The transmission control relay is used to supply power to the solenoid pack when the transmission is in normal operating mode. When the relay is off, no power is supplied to the solenoid pack and the transmission is in Limp-in mode. The relay output is fed back to the PCM. It is referred to as the Trans Relay Output circuit or switched battery.

Transmission Effects: The MIL will illuminate and the transmission system defaults to Logical Limp-in mode. Logical Limp-in mode results in the same modes of operation as Limp-in. Since the relay is stuck "on", the PCM can not open the relay, and the PCM shifts to 2nd gear.

Possible Causes:

Relay (welded contacts)
Short to battery in 12-volt supply and/or Transmission Control Relay Output circuit(s)
Short to voltage
PCM connector problems
PCM

Name Of Code: P0888(15) - Relay Output Always Off

When Monitored: Continuously

Set Condition: This code is set when less than 3 volts are present at the Trans Relay Output (switched battery) terminals at the PCM when the PCM is energizing the relay.

After a controller reset (ignition key turned to the run position or after cranking engine), the controller energizes the relay. Prior to this the PCM verifies that the contacts are open by checking for no voltage at the switched battery terminals. After the relay is energized, the PCM monitors the terminals to verify that the voltage is greater than 3 volts.

Transmission Effects: The MIL illuminates and the transmission system defaults to Limp-in mode.

Possible Causes:

Relay failure (intermittent relay function caused by oxidized or contaminated relay contacts)
Short to ground or open circuit in the Transmission Control Relay circuit(s)
PCM connector problem
PCM

Name Of Code: P0725(18) - Engine Speed Sensor Circuit

NOTE: This code is not a Transmission Input Speed Sensor DTC

When Monitored: Whenever the engine is running.

Set Condition: This code is set when the engine speed sensed by the Transmission Control System is less than 390 RPM or greater than 8000 RPM for more that 2.0 seconds.

Theory Of Operation: The PCM uses a new dual port RAM internal to the controller to send the Crank Sensor signal to the Transmission Control System. If the PCM interprets this signal to be out of range when the engine is running the code is set.

Transmission Effects: The MIL illuminates and the transmission system defaults to Limp-in mode.

Possible Causes:

Engine DTC (engine RPM related) present
PCM

Name Of Code: P1694(19) - Bus Communication with Engine Module

When Monitored: Continuously with key on.

Set Condition: If no PCI bus messages are received from the Powertrain Control Module (PCM) for 10 seconds.

Theory Of Operation: The Transmission Control System communicates with the engine control system using the PCI bus. It relies on certain information to function properly. The Transmission Control System continuously monitors the PCI bus to check for messages broadcast from the engine control system.

Transmission Effects: Delayed 3-4 shifts. No EMCC and early 3-4 shifts for a few minutes after engine is started.

Possible Causes:

Open or shorted PCI bus circuit
PCM

Name Of Code: P0890(20) - Switched Battery

When Monitored: Ignition key is turned from off position to run position and/or ignition key is turned from crank position to run position.

Set Condition: This code is set if the PCM senses voltage on any of the pressure switch inputs prior to the PCM energizing the relay.

Immediately after a controller reset (ignition key turned to the run position or after cranking engine), the PCM verifies that the relay contacts are open by checking for no voltage at the switched battery terminals. After this is verified, the voltage at the Solenoid Pack pressure switches is checked. There should be no voltage on the pressure switches at this time. The PCM will then activate the relay.

Transmission Effects: The MIL illuminates and the transmission system defaults to Limp-in mode.

Possible Causes:

Short to battery on one or more pressure switch sense circuits
PCM connector problems
PCM

Name Of Code: P0871(21) - OD Pressure Switch Sense Circuit

When Monitored: Whenever the engine is running.

Set Condition: This code is set if the OD pressure switch is open or closed at the wrong time in a given gear (see chart below).

Theory Of Operation: The Transmission system uses three pressure switches to monitor the fluid pressure in the LR, 2/4, and OD clutch circuits. The pressure switches are continuously monitored for the correct states in each gear as shown below.

PRESSURE SWITCH STATES

SWITCHES	R	N	1ST	2ND	3RD	4TH
L/R	OPEN	CLOSED	CLOSED	OPEN	OPEN	OPEN
2/4	OPEN	OPEN	OPEN	CLOSED	OPEN	CLOSED
O/D	OPEN	OPEN	OPEN	OPEN	CLOSED	CLOSED

Transmission Effects: Normal operation will be experienced if no other codes are present. PCM will ignore the code. Limp-in condition will only occur if code P0871(21) is present with a code P0706(28).

Possible Causes:

If code P0944(35) is present, ignore code P0871(21) and perform code P0944 diagnostic procedures
OD pressure switch sense circuit open or shorted to ground between PCM and solenoid pack
OD pressure switch sense circuit shorted to battery
Solenoid pack
Loose valve body bolts
Plugged filter - internal transmission or torque converter failure
PCM

Name Of Code: P0846(22) - 2/4 Pressure Switch Sense Circuit

When Monitored: Whenever the engine is running.

Set Condition: This code is set if the 2/4 pressure switch is open or closed at the wrong time in a given gear (see chart below).

Theory Of Operation: The Transmission system uses three pressure switches to monitor the fluid pressure in the LR, 2/4, and OD elements. The pressure switches are continuously monitored for the correct states in each gear as shown below.

Transmission Effects: If the 2/4 pressure switch is identified as closed in P or N, the code will immediately be set and normal operation will be allowed for that given key start. If the problem is identified for 3 successive key starts, the transmission will go into Limp-in mode.

If the 2/4 pressure switch is identified as being closed in 1st or 3rd gear and was not identified as being closed in P or N, then 2nd gear or 4th gear will be substituted for 1st or 3rd gear depending on

PRESSURE SWITCH STATES

SWITCHES	R	N	1ST	2ND	3RD	4TH
L/R	OPEN	CLOSED	CLOSED	OPEN	OPEN	OPEN
2/4	OPEN	OPEN	OPEN	CLOSED	OPEN	CLOSED
O/D	OPEN	OPEN	OPEN	OPEN	CLOSED	CLOSED

throttle angle and vehicle speed. A short period of time after the gear substitution, the transmission will return to normal operating mode. If the transmission is shifted back into 1st or 3rd gear through normal operation, and the 2/4 pressure switch remains closed, 2nd or 4th gear will be substituted briefly and then resume normal operation. If four gear substitutions occur in a given key start, the transmission will go into Limp-in mode.

If the 2/4 pressure switch is open (indicating no 2/4 clutch pressure) in 2nd or 4th gear, the PCM sets code P0846(22) and continues with normal operation. The transmission will only go into Limp-in mode if a code P0706(28) is also present. If no 2/4 clutch pressure is present a gear ratio code P0732(52) or P0734(54) will be set and cause the limp-in condition.

Possible Causes:

If code P0944(35) is present, ignore code P0846(22) and perform code P0944 diagnostic procedures
2/4 pressure switch sense circuit open or shorted to ground between PCM and solenoid pack
2/4 pressure switch sense circuit shorted to battery
Solenoid pack
Transmission overheated - Excessive regulator valve leakage in valve body causing high line pressure which results in 2/4 solenoid blow-off in 1st or 3rd gear. May require new valve body if it happens only when hot.
Loose valve body bolts
Plugged filter - internal transmission or torque converter failure
PCM

Name Of Code: P0841(24) - LR Pressure Switch Sense Circuit

When Monitored: Whenever the engine is running.

Set Condition: This code is set if the LR pressure switch is either open or closed at the wrong time in a given gear.

PRESSURE SWITCH STATES

SWITCHES	R	N	1ST	2ND	3RD	4TH
L/R	OPEN	CLOSED	CLOSED	OPEN	OPEN	OPEN
2/4	OPEN	OPEN	OPEN	CLOSED	OPEN	CLOSED
O/D	OPEN	OPEN	OPEN	OPEN	CLOSED	CLOSED

Transmission Effects: If a set condition is identified, 1st gear and torque converter lock-up (EMCC) will be inhibited. The vehicle will launch in 2nd gear and shift normally through the gears without allowing EMCC. If during the same key start, the set condition is no longer valid, the transmission will return to normal operation (1st and EMCC available). Limp-in will not occur unless code P0841(24) is accompanied by a code P0706(28) and the MIL will illuminate after 5 minutes of substituted operation.

Possible Causes:

If code P0944(35) is present, ignore code P0841(24) and perform code P0944(35) diagnostic procedures
LR pressure switch sense circuit open or shorted to ground between PCM and solenoid pack
LR pressure switch sense circuit shorted to battery
Solenoid pack
Valve body - solenoid switch valve stuck in LU position. May be accompanied by a code P1775(37)
Loose valve body bolts
Plugged filter - internal transmission or torque converter failure
PCM

Name Of Code: P0706(28) - Check Shifter Signal

When Monitored: Continuously with the key on.

Set Condition: 3 occurrences in one key start of an invalid PRNDL code which lasts for more than 0.1 second.

Theory of Operation: The C1 through C4 (T1, T3, T41, and T42) sense circuits communicate the shift lever position to the PCM. Each circuit is terminated at the transmission with a switch. Each switch can be either open or closed, depending on the shift lever position. The PCM can decode this information and determine the shift lever position. Each shift lever position has a certain combination of switches which will be open and closed, this is called a PRNDL code. There are 4 switches, therefore: there are many possible combinations of open and closed switches (codes). However, there are only 9 valid codes (8 for AutoStick), one for each gear position and three recognized between gear codes. The remainder of the codes should never occur, these are called invalid codes. The following chart shows the normal switch states for each shift lever position.

Fig 1: Shift Lever Position Chart

Courtesy of DAIMLERCHRYSLER CORP.

The following are DRBIII® reported Shift Lever Error Codes (chart)

SHIFT LEVER ERROR CODES

ERROR CODE	SWITCH STUCK	POSITION
1	T1/C4 STUCK	OPEN
2	T1/C4 STUCK	CLOSED
3	T3/C3 STUCK	OPEN
4	T3/C3 STUCK	CLOSED
5	T42/C2 STUCK	OPEN
6	T24/C2 STUCK	CLOSED
7	T41/C1 STUCK	OPEN
8	T41/C1 STUCK	CLOSED

Transmission Effects and possible causes: Scenario 1) - All PRNDL lights stay illuminated indefinitely in Park following a Key start.

Wrong Part Number PCM for application
TRS connector not plugged in
C1 through C4 (T1, T3, T41, or T42) circuits are open, shorted to ground, or shorted to 12 volts.
PCI bus failure (Open or shorted resulting in no communication to BCM or Cluster)
TRS
PCM
BCM

Scenario 2) - "P" is indicated following a key start but all PRNDL lights illuminate in "N" following a shift from "R" to "N". If PRNDL lights illuminate in "N" and shifter is moved directly into "3" or "L" position without pausing in "OD", then the "OD" position shift schedule and electronic display will indicate "OD" until the shifter is shifted into the "OD" position and held for at least 3 seconds.

Worn Manual Lever (Rooster Comb). Check for heavy wearing of TRS switch contacts
Intermittent C1 through C4 (T1, T3, T41 or T42) circuits. Check for corrosion, terminal push-outs or spread terminals at PCM or TRS switch 10-way connector
TRS
PCM
BCM

Scenario 3) - If an invalid code happens while operating in the "3" or "L" position, the "3" or "L" shift schedule and electronic display will be frozen (regardless of whether "OD", "3" or "L" is selected). The display will be frozen until the shifter is moved to the "N" position (all PRNDL lights will illuminate) and then back to the "OD" position. The "N" and "OD" position must be held for at least 3 seconds in each position to resume the normal "OD" shift schedule and electronic display.

Intermittent C1 through C4 (T1, T3, T41 or T42) circuits. Check for corrosion, terminal push-outs or spread terminals at PCM and/or TRS connector
TRS
PCM
BCM

These same symptoms may occur without the code P0706(28) getting set. It is possible that the invalid code that was sensed by the PCM only occurred once or twice during the given ignition key start and/or did not last for longer than 0.1 second.

Name Of Code: P0124(29) - Throttle Position Sensor/APPS Intermittent; P0122(2A) - Throttle Position Sensor/APPS Low; P0123(2B) - Throttle Position Sensor/APPS High

When Monitored: Whenever the key is on or the engine is running. Engine speed > 500 RPM

Set Condition:

P0124 - Throttle angle change > 5° in 7 milliseconds the Fault set time milliseconds 0.448 seconds

P0122 - Throttle angle < 6° the Fault Set Time: 0.448 seconds

P0123 - Throttle angle > 120.6° the Fault Set Time: 0.448 seconds

Theory Of Operation: The transmission controller receives the throttle position signal and its ground from the Throttle Position Sensor (TPS). The TPS has a 5 volt pull up supplied by the engine controller. The throttle signal is checked for out-of-range as well as intermittents (excessive signal changes). The engine controller transmits the throttle value via the Dual Port RAM. Most engine controllers can synthesize the throttle value if the throttle position sensor signal is lost. If a throttle error is detected by the transmission controller and the throttle value is available via the Dual Port RAM, the Dual Port RAM throttle value will be used and normal operation will continue, however a throttle fault code will be set. If a throttle error is detected and the throttle value is not available via the Dual Port RAM, normal operation will be discontinued, a throttle fault code will be set, and the MIL will be turned on after 5 min. of substituted operation.

Transmission Effects:

If throttle value available via the Dual Port RAM-No effect.
If throttle value not available via the Dual Port RAM
A default throttle value is used.

Torque converter lock-up inhibited.

4th gear inhibited.

Limited shift schedule.

MIL on after 5 min. of substituted operation.
Possible Causes:
1. Wiring problem
2. TPS
3. PCM

Name Of Code: P0870(31) - OD Hydraulic Pressure Test Failure; P0845(32) - 2/4 Hydraulic Pressure Test Failure; P0992(33) - 2-4/OD Hydraulic Pressure Test Failure

When Monitored: In 1st, 2nd, or 3rd gear with engine speed above 1000 RPM shortly after a shift and every minute thereafter.

Set Condition: Immediately after a shift into 1st, 2nd, or 3rd gear, with engine speed above 1000 RPM, the PCM momentarily turns on element pressure to the 2/4 and/or OD clutch circuits to identify that the appropriate pressure switch closes. If the pressure switch does not close it is tested again. If the switch does not close the second time, the appropriate code is set.

Theory Of Operation: The Transmission Control System tests the OD and 2/4 pressure switches when they are off (OD and 2/4 are tested in 1st gear, OD in 2nd gear, and 2/4 in 3rd gear). The test verifies that the switches are operational. The PCM verifies that the switch closes when the corresponding element is applied. If a switch fails to close, it is retested, If it fails the second test, the code is set.

Transmission Effects: The MIL illuminates and the transmission system defaults to Limp-in mode.

Possible Causes:

Pressure switch sense circuit shorted to battery between PCM and solenoid pack.
Low line pressure
Solenoid Pack

PRESSURE SWITCH STATES

SWITCHES	R	N	1ST	2ND	3RD	4TH
L/R	OPEN	CLOSED	CLOSED	OPEN	OPEN	OPEN
2/4	OPEN	OPEN	OPEN	CLOSED	OPEN	CLOSED
O/D	OPEN	OPEN	OPEN	OPEN	CLOSED	CLOSED

Name Of Code: P0944(35) - Loss Of Prime

When Monitored: If the transmission is slipping in any forward gear and the pressure switches are not indicating pressure, a loss of prime test is run.

Set Condition: If the transmission begins to slip in any forward gear, and the pressure switch or switches that should be closed for a given gear are open, a loss of prime test begins. All available elements (in 1st gear LR, 2/4 and OD, in 2nd, 3rd, and 4th gear 2/4 and OD) are turned on by the PCM to see if pump prime exists. The code is set if none of the pressure switches respond. The PCM will continue to run the loss of prime test until pump pressure returns.

Theory Of Operation: The loss of prime test is used to prevent transmission faults, which can be caused by a lack of pump prime.

Transmission Effects: Vehicle will not move or transmission slips. Normal operation will continue if pump prime returns.

Possible Causes:

Low transmission fluid level
PRNDL indicates a valid OD code in the hydraulic reverse position
Transmission fluid filter clogged or damaged
Transmission fluid filter improperly installed (Bolts loose or O-ring missing)
Oil pump - If a customer has a problem when the transmission is cold. Where someone shifts to reverse, reverse is engaged, and then shifts to OD and does not get OD (gets a neutral condition), and then can not get reverse or OD for 3-20 seconds, replace the oil pump. High side clearance in the oil pump will set a code 35. The pump will prime upon start-up, but as the torque converter purges air (drain down) the air will leak across the inner rotor into the pump suction port and cause a loss of prime right after the shift into OD. After 3 - 20 seconds, pump prime will return and normal operation will continue. The pump should be replaced only after all other possible causes above have been checked and verified.

Name Of Code: P1790(36) - Fault Immediately After Shift

When Monitored: After a gear ratio error is stored.

Set Condition: This code is set if the associated gear ratio code is stored within 1.3 seconds after a shift.

Theory Of Operation: This code will only be stored along with a 50 series code. If this code is set, it indicates the problem is mechanical in nature. When this code exists, diagnosing the transmission should be based on the associated gear ratio code and primarily mechanical causes should be considered.

Transmission Effects: None

Possible Causes:

Mechanical causes as listed under associated gear ratio code.

Name Of Code: P1775(37) - Solenoid Switch Valve Latched in TCC Position

When Monitored: During an attempted shift into 1st gear.

Set Condition: This code is set if three unsuccessful attempts are made to get into 1st gear in one given key start.

Theory Of Operation: The solenoid switch valve (SSV) controls the direction of the transmission fluid when the LR/TCC solenoid is energized. The SSV will be in the downshifted position in 1st gear, thus directing the fluid to the LR clutch circuit. In 2nd, 3rd, and 4th, it will be in the upshifted position and directs the fluid into the torque converter clutch (TCC).

When shifting into 1st gear, a special hydraulic sequence is performed to ensure SSV movement into the downshifted position. The LR pressure switch is monitored to confirm SSV movement. If movement is not confirmed (the LR pressure switch does not close), 2nd gear is substituted for 1st.

Transmission Effects: Transmission will have no 1st gear (2nd gear will be substituted), and no EMCC operation and the MIL will illuminate after 5 minutes of substituted operation

Possible Causes:

PRNDL indicates a valid OD code in the hydraulic reverse position
Valve body - Solenoid valve stuck in TCC position
High idle speed
Solenoid malfunction - LR pressure switch will not close
LR Pressure Switch Sense circuit shorted to battery

Name Of Code: P0740(38) - Torque Converter Clutch Control Circuit

When Monitored: During Electronically Modulated Converter Clutch (EMCC)

Set Condition:

The transmission must be in EMCC, with the input speed greater than 1750 RPM. The TCC/LR solenoid must achieve it's maximum duty cycle and still not be able to pull the engine speed within 60 RPM of input speed.
If the transmission is in FEMCC and the engine can slip the TCC by more than 100 RPM (Engine speed - Input speed) for 10 seconds.

The code will be set if one of these event happens three times at a throttle angle less than 30 degrees. Theory Of Operation: When in 2nd, 3rd, or 4th gear, the torque converter clutch (TCC) can be locked when certain conditions are met. The TCC piston is electronically modulated by increasing the duty cycle of the LR/TCC solenoid until the torque converter slip difference (difference between engine and turbine speed) is within 60 RPM. Then the LR/TCC solenoid is fully energized (FEMCC/100% duty cycle). Torque converter slip is monitored in FEMCC to ensure adequate clutch capacity.

Transmission Effects: EMCC will still be available after code is set. MIL will illuminate after 5 minutes of accumulated slip in FEMCC. The transmission will attempt normal operation (not in Limp-in) even after the MIL is illuminated.

Possible Causes:

Worn pump bushing and/or failed torque converter - both should be replaced during a rebuild with code P0740(38) present
Solenoid pack.

Name Of Code: P0750(41) - LR Solenoid Circuit P0755(42) - 2/4 Solenoid Circuit; P0760(43) - OD Solenoid Circuit; P0765(44) - UD Solenoid Circuit

When Monitored: Ignition key is turned from off position to run position and/or ignition key is turned from crank position to run position, then every 10 seconds thereafter, or when a gear ratio or pressure switch error DTC is detected.

Set Condition: All four solenoids are tested for continuity continuously immediately upon start up and during vehicle operation. For solenoids that are currently energized, power is momentarily interrupted, then reenergized. For solenoids that are not currently energized, the solenoid is momentarily energized, then de-energized. Under both situations, if an inductive spike is not sensed by the PCM during the continuity check, it is retested twice. If it fails the test the third time, the appropriate code is set.

SOLENOID APPLICATION CHART

GEAR	UD	OD	REV	2/4	LR
PARK					X
REVERSE			X		X
NEUTRAL					X
1ST	X				X
2ND	X			X
3RD	X	X
4TH		X		X

Theory Of Operation: Four solenoids are used to control the friction elements (clutches). The continuity of the solenoids circuits are periodically tested. Each solenoid is turned on or off depending on it's current state. An inductive spike should be detected by the PCM during this test. If no spike is detected, the circuit is tested again to verify the failure. In addition to the periodic testing, the solenoid circuits are tested if a gear ratio or pressure switch error occurs. In this case, one failure will result in the appropriate code being set.

Transmission Effects: The MIL will illuminate and the transmission goes into neutral if code is set above 35 Km/h (22 MPH), Limp-in mode when vehicle speed is below 35 Km/h (22 MPH).

Possible Causes:

Open or shorted solenoid circuit(s) between PCM and solenoid pack.
Open ground circuit.
PCM connector problems.
Solenoid pack connector problem.
Solenoid Pack.
PCM

Name Of Code: P1776(47) - Solenoid Switch Valve Latched in LR Position

When Monitored: Continuously when doing partial or full EMCC (PEMCC or FEMCC)

Set Condition: If the transmission senses the LR pressure switch closing while performing PEMCC or FEMCC. This code will be set after two unsuccessful attempts to perform PEMCC or FEMCC.

Theory Of Operation: The solenoid switch valve (SSV) controls the direction of the transmission fluid when the LR/TCC solenoid is energized. SSV will be in the downshifted position in 1st gear, thus directing the fluid to the LR clutch circuits. In 2nd, 3rd, and 4th, the SSV will be in the upshifted position and directs the fluid into the torque converter clutch (TCC).

When doing PEMCC or FEMCC, the LR pressure switch should indicate no pressure if the SSV is in the TCC position. If the LR pressure switch indicates pressure while in PEMCC or FEMCC, EMCC operation is aborted and inhibited to avoid inadvertent application of the LR clutch. Partial EMCC will be attempted if the LR pressure switch does not indicate pressure. A second detection of LR pressure results in setting the code.

Transmission Effects: At speeds above 72 Km/h (45 MPH), EMCC is inhibited. Once speed falls below 72 Km/h (45 MPH), the transmission will go into Limp-in mode and the MIL will illuminate after 5 minutes of substituted operation.

Possible Causes:

Valve body - Solenoid valve stuck in LR position
Intermittent short to ground or open circuit in LR Pressure Switch Sense circuit (with code 24 only)
Solenoid pack (with code P0841(24) only)
PCM (with code P0841(24) only)

Name Of Code: P0736(50) - Gear Ratio Error in Reverse; P0731(51) - Gear Ratio Error in 1st; P0732(52) - Gear Ratio Error in 2nd; P0733(53) - Gear Ratio Error in 3rd; P0734(54) - Gear Ratio Error in 4th; P0715(56) - Input Speed Sensor Error; P0720(57) - Output Speed Sensor Error; P1794(58) - Speed Sensor Ground Error

When Monitored: The transmission gear ratio is monitored continuously while the transmission is in gear.

Set Condition: This code is set if the gear ratio is not correct for a period of time.

Codes 50 through 54 sets if the ratio of the input RPM (Nt) to the output RPM (No) does not match the given gear ratio.
Code 56 sets if there is an excessive change in input RPM in any gear
Code 57 sets if there is an excessive change in output RPM in any gear
Code 58 sets after a TCM reset in neutral and Nt/No equals a ratio of input to output of 2.50

A hard code sets within 3 seconds, an intermittent code sets within 15 seconds.

Theory Of Operation: The transmission system uses two speed sensors, one to measure input RPM and one to measure output RPM. These inputs are essential for proper transmission operation. Therefore, the integrity of this data is verified through the following checks:

When in gear, if the gear ratio does not compare to a known gear ratio, the corresponding in-gear trouble code is set (codes 50 through 54).
An excessive change in input or output speeds indicating signal intermittent will result in codes 56 and/or 57 being set.
After a PCM reset in neutral, observing erratic output and input speed sensor signals indicates a loss of the common speed sensors ground. This sets a code 58.

Transmission Effects: The transmission will not go into Limp-in mode until three gear ratio error events occur in a given key start also the MIL will illuminate after 5 minutes of substituted operation. This allows for intermittent problems to correct themselves without opening the relay. However, if a gear ratio error develops, a code is always set, but if the condition corrects itself the transmission will continue without requiring the ignition key to be cycled on and off. Many different events could occur given the range of failures possible for codes 50 through 58. The following are a few examples:

Codes 51, 52, 53, 54, 56, and 57 at speeds above 72 Km/h (45 MPH) - The appropriate code is set, EMCC is aborted and current gear is maintained. If while still traveling above 72 Km/h (45 MPH), the gear ratio becomes valid again, EMCC will reengage and normal operation will resume. If the gear ratio becomes intermittent and recovers three times in a given key start, the current gear will be maintained and EMCC inhibited, then the transmission will go into Limp-in mode if throttle is applied below 72 Km/h (45 MPH) or at 35 Km/h (22 MPH) with closed throttle.
Codes 51, 52, 53, 54, 56, and 57 at speeds between 35 and 72 Km/h (22 and 45 MPH) - If one of these codes is set between 35 and 72 Km/h (22 and 45 MPH), the current gear will be maintained until the gear ratio problem corrects itself. If throttle is applied, the trans will go to 2nd gear. If this happens and the gear ratio problem goes away, normal operation will resume. If three gear ratio problems are identified in a given key start, the current gear will be frozen until throttle is applied. The transmission will then go into Limp-in mode with throttle applied at speeds between 35 and 72 Km/h (22 and 45 MPH)
Codes 51, 52, 53, 54, 56, and 57 at speeds below 35 Km/h (22 MPH) - If a gear ratio problem is identified below 35 Km/h (22 MPH), the transmission will immediately substitute second gear for the current gear. If the gear ratio problem goes away, normal operation will resume. If three gear ratio problems are identified in a given key start, the transmission will go into Limp-in mode.

Possible Causes:

Code P0736(50) - Excludes geartrain failures which should be obvious upon disassembly

If code P0944(35) is also set, follow diagnostic procedure for code P0944(35) first
Valve body - #1 ball check or LR switch valve sticking - may also set code P0731(51)
Speed sensor or associated wiring - may also set codes P0731(51), P0715(56), or P0720(57)
Failed or slipping LR clutch - may also set code P0731(51)
- LR seal leakage (Intermittent no drive or reverse)
- Sticky LR accumulator seals (Intermittent no drive or reverse)
Failed reverse clutch (hard code)
- OD/Rev lip seal leakage
- Worn reaction shaft support seal rings
- Snap ring out of position
Code P0731(51) - Excludes geartrain failures which should be obvious upon disassembly
If code P0944(35) is also set, follow diagnostic procedure for code P0944(35) first
Valve body - #1 check ball or LR switch valve sticking - may also set code P0736(56) or have no Reverse
Speed sensor or associated wiring - may also set codes P0736(50), P0715(56), or P0720(57)
Failed or intermittent slipping UD clutch - may also set P0732(52), or P0733(53)
- UD seal leakage (intermittent)
- Worn input clutch hub bushing (hard code at heavy throttle)
- Sticky UD accumulator seals (intermittent)
- Worn reaction shaft support seal rings (hard code at heavy throttle)
- Solenoid pack (UD pressure in 4th gear)
Failed or slipping LR clutch - may also set code P0736(56) or have no Reverse
- LR seal leakage (Intermittent)
- Sticky LR accumulator seals (Intermittent)
Code P0732(52) - Excludes geartrain failures which should be obvious upon disassembly
If code P0944(35) is also set, follow diagnostic procedure for code P0944(35) first
Failed or slipping 2/4 clutch - may also set code P0734(54)
- 2/4 seal leakage (intermittent)
- Sticky accumulator seals (intermittent)
Failed or intermittent slipping UD clutch - may also set code P0731(51) and/or P0733(53)
- UD seal leakage (intermittent)
- Worn input clutch hub bushing (hard code at heavy throttle)
- Sticky UD accumulator seals (intermittent)
- Worn reaction shaft support seal rings (hard code at heavy throttle)
- Solenoid pack (UD pressure in 4th gear)
Code P0733(53) - Excludes geartrain failures which should be obvious upon disassembly
If code P0944(35) is also set, follow diagnostic procedure for code P0944(35) first
Failed or slipping OD clutch - may also set code P0734(54)
- OD and Reverse inner and outer lip seal leakage (usually hard code)
- Sticky OD accumulator seals (intermittent)
- Worn reaction shaft support seal rings (hard code at heavy throttle)
- Broken OD/UD tapered snap ring - (hard code at heavy throttle)
Failed or intermittent slipping UD clutch - may also set code P0731(51) and/or P0732(52)
- UD seal leakage (intermittent)
- Worn input clutch hub bushing (hard code at heavy throttle)
- Sticky UD accumulator seals (intermittent)
- Worn reaction shaft support seal rings (hard code at heavy throttle)
- Solenoid pack (UD pressure in 4th gear)
Code P0734(54) - Excludes geartrain failures which should be obvious upon disassembly
If code P0944(35) is also set, follow diagnostic procedure for code P0944(35) first
Failed or slipping OD clutch - may also set code P0733(53)
- OD and Reverse inner and outer lip seal leakage (usually hard code)
- Sticky OD accumulator seals (intermittent)
- Worn reaction shaft support seal rings (hard code at heavy throttle)
- Broken OD/UD tapered snap ring - (hard code at heavy throttle)
Failed or slipping 2/4 clutch - may also set code P0732(52)
- 2/4 seal leakage (intermittent)
- Sticky accumulator seals (intermittent)
Codes P0715(56) and P0720(57)
Failed input or output speed sensor (intermittent or hard code)
Shorted or open wiring between PCM and speed sensor(s) (intermittent)
Connector problems at PCM connector and/or speed sensor connector
Code P1794(58)
Open or shorted speed sensor ground (speed sensor ground is different from chassis ground)
Open or shorted Temperature Sensor wiring to TRS
TRS - Will also set code P1799(74)
PCM

Name Of Code: P0952(69)- AutoStick Sensor Circuit Low (If equipped)

When Monitored: Whenever the engine is running.

Set Condition:

The transmission shift lever is not in AutoStick and either the upshift or downshift switch is closed.
Upshift and downshift switches closed at the same time.

Theory Of Operation: In the AutoStick Mode (manual shift mode), upshifts and downshifts are actuated manually. Shift requests are detected by monitoring the upshift and downshift switches. The PCM monitors the above set conditions. A set condition will be tolerated for up to 15 seconds before setting a code.

Transmission Effects: The OD position shift schedule is substituted while operating in the AutoStick gear selector position. No Limp-in mode occurs.

Possible Causes:

Wiring or connector problems
AutoStick switch failure
PCM

Name Of Code: P1797(71)- Manual Shift Overheat

When Monitored: Whenever the engine is running.

Set Condition:

If the engine temperature exceeds 124 C (255°F) while operating in AutoStick mode.
If the transmission temperature exceeds 135°C (275°F) while in AutoStick mode

Theory Of Operation: Transmission and engine temperatures are monitored during vehicle operation. If conditions occur causing the engine or transmission to overheat, the AutoStick mode will be canceled, and a code will be set.

Transmission Effects: The 3 position shift schedule that is used in non-AutoStick applications is substituted while operating in the AutoStick gear selector position. No Limp-in mode occurs.

Possible Causes:

Engine overheat - refer to service information for diagnosis and repair
Transmission Overheat
- Restricted transmission cooling system
- Transmission fluid overfilled
- Radiator fan not functioning properly
- Extended driving in low gear

NOTE: Strenuous driving conditions may cause the vehicle to overheat. If the driver operates in or initiates AutoStick with an overheated vehicle, the code will be set.

Name Of Code: P0897(73) - Worn Out/Burnt Transmission Fluid

When Monitored: At every Fully Electronically Modulated Converter Clutch (FEMCC) to Partial Electronically Modulated Converter Clutch (PEMCC) transition miles when A/C compressor clutch is being cycled.

Set Condition: The code will be set if vehicle shudder is detected 20 times when the A/C clutch is cycled.

Theory Of Operation: While in 3rd or 4th gear FEMCC and just before the A/C clutch engages, the Engine Control System requests the Transmission Control System to momentarily establish PEMCC operation. If vehicle shudder is detected during the FEMCC to PEMCC transition, a counter is incremented. If the count reaches 20, the trouble code is set. The driver may then notice harsh bumps when the A/C clutch is being cycled, but vehicle shudder will be eliminated. After 35 OBDII (EURO STAGE III OBD) warm-up starts or if the code is cleared, PEMCC will be reactivated to see if shudder is still present. If one shudder event occurs, the code will be reset. Clearing the code and running battery disconnect with the DRBIII® is the only way to reset the shudder counter from 20 back to zero.

Transmission Effects: This code does not cause the transmission to go into Limp-in mode. However, once the code is set, FEMCC to PEMCC operation before the A/C clutch engagement will be disabled for 35 OBDII (EURO STAGE III OBD) warm up starts.

Possible Causes:

Degraded transmission fluid
Wheels severely out of alignment
Internal torque converter problem

Name Of Code: P0218(75) - High Temperature Operation Activated.

When Monitored: Whenever the engine is running.

Set Condition: Immediately once the Overheat Shift Schedule is activated.

Theory Of Operation: If the transmission oil temperature rises above 115°C (240°F), the overheat shift schedule is activated refer to Transmission Operation as a function of Transmission Oil Temperature and the code is set. The DTC is an information code only and is being set to aid the technician in determining root cause of a customer driveability issue. The code is also intended to alert the technician to determine if a cooling system malfunction has occurred or if an additional transmission air to oil cooler should be added to the vehicle if the customer regularly drives in a manner that overheats the transmission. Extended operation above 115°C (240°F) will reduce the durability of the transmission and should be avoided. Correcting the cooling system malfunction or installing an additional transmission oil cooler will improve transmission durability especially for customers who operate in city/construction stop and go traffic, tow trailers regularly, drive aggressively in low gear or drive regularly in mountainous areas.

Transmission Effects: Information only code. - Overheat shift schedule was activated, no Limp-in condition occurs. 2nd gear partial EMCC above 40 Km/h (25 MPH), 3rd gear EMCC from 45-69 Km/h (28-43 MPH), delayed 3-4 upshift at 69 Km/h (43 MPH), early 4-3 coastdown at 66 Km/h (41 MPH), EMCC operation under all conditions above 40 Km/h (25 MPH) except at closed throttle or 1st gear.

Possible Causes:

Transmission Overfilled with Oil
Engine cooling fan failure
Engine thermostat stuck closed
Radiator corroded or packed with dirt
Transmission Oil Cooler Plugged
Customer driving pattern requires additional transmission cooling

Name Of Code: P0884(76) - Power Up at Speed

When Monitored: When PCM (transmission control module) initially powers-up.

Set Condition: If the PCM powers up while in the "Drive" position and the vehicle is going above 32 Km/h (20 MPH), the code is set.

Theory of Operation: If a vehicle loses power to the PCM, the vehicle will go to the 2nd gear mode since there is no power available to control the transmission solenoids. However if power is restored, the PCM will power-up and normal operation will be restored. This DTC identifies that power to the PCM was restored when the gear selector was in a "Drive" position while the vehicle was moving at speeds above 32 Km/h (20 MPH). If someone shifts to Neutral and cycles the ignition key and quickly shifts to "Drive" while moving before the PCM comes out of its START ROUTINE, the DTC can be set. Therefore it is critical that this DTC diagnosis repair procedure should only be used if the vehicle is experiencing intermittent 2nd gear operation and subsequently a return to normal operation during normal driving.

Transmission Effects: No Limp-in condition. The DTC is for information only when trying to diagnosis intermittent 2nd gear operation and subsequently a return to normal operation.

Possible Causes:

No Problem if vehicle is started in "neutral" at speeds above 32 Km/h (20 MPH) and shifted quickly to "Drive" before TCM comes out of the START ROUTINE.

FOR INTERMITTENT 2ND GEAR OPERATION AND THEN A SUBSEQUENT RETURN TO NORMAL OPERATION WITHOUT CYCLING THE IGNITION KEY

Intermittent Direct Battery connection between PCM and battery.
Intermittent Fused Ignition Switch Output between PCM and ignition switch.
Intermittent Ground to PCM.

Name Of Code: P1687(77) - No Communication with the MIC

When Monitored: Continuously with key on.

Set Condition: If no PCI bus messages are received from the Mechanical Instrument Cluster (MIC) for 25 seconds.

Theory Of Operation: The Transmission Control System communicates with the MIC using the PCI bus. It relies on certain information to function properly. The Transmission Control System continuously monitors the PCI bus to check for messages broadcast from the Engine Control System.

Transmission Effects: Possible improper PCM AutoStick configuration.

Possible Causes:

Open or shorted PCI bus circuit from MIC
MIC
PCM

Name Of Code: P1652(78) - Serial Communication Link Malfunction

When Monitored: Continuously with key on.

Set Condition: If no PCI bus messages are received by the Transmission Control System for 10 seconds.

Theory Of Operation: The Transmission Control System communicates with the other modules in the vehicle using the PCI bus. It relies on certain information to function properly. The PCM continuously monitors the PCI bus to check for messages broadcast from the certain modules.

Transmission Effects: Possible improper PCM AutoStick configuration and delayed 3-4 shifts. No EMCC and early 3-4 shifts for a few minutes after engine is started.

Possible Causes:

Open or shorted PCI bus circuit from BCM
PCM

Name Of Code: P0562(79) Low Battery Voltage

When Monitored: Continuously with engine running and Transmission Relay energized.

Set Condition: If the battery voltage of the Transmission Control Relay Output Sense circuit(s) to the PCM is less than 10.0 volts for the period of 15 seconds. The DTC will also set if the direct battery voltage sensed in the PCM is less than 6.5v for 200ms or where Transmission Control Relay Output Sense circuit (switched battery) is less than 7.2v for 200ms. Note: P0562 generally indicates a gradually falling battery voltage or a resistive connection(s) to the PCM.

Theory Of Operation: The Transmission system requires sufficient battery voltage in order to energize the transmission solenoids. The PCM continuously monitors the voltage available to the solenoids.

Transmission Effects: At speeds above 72 Km/h (45 MPH) the transmission system will default to neutral. Below 72 Km/h (45 MPH) the transmission system will default to Limp-in mode and the MIL will illuminate after 5 minutes of substituted operation. Manual gear selection of Park, Reverse, Neutral and Second will be available.

Possible Causes:

Charging system problem
Poor/High resistance connection between PCM and Battery/Alternator
PCM high resistance or poor connection
PCM ground high resistance or poor connection
High resistance in Transmission Control Relay contacts
PCM

Name Of Code: P0711(7A) - Transmission temperature sensor performance

When Monitored: Every 7 milliseconds with the engine running and no loss of prime DTC set.

Set Condition: A temperature reading of 80°F is not reached in the specified period of time

Theory Of Operation: The temperature sensor (thermistor) is used to sense the temperature of the transmission fluid. Transmission fluid temperature can affect shift quality, torque converter lockup, and when and if some diagnostics are run. A failed temperature sensor could affect the OBD II diagnostics, therefore when a fault is detected in the temperature sensor circuit, transmission temperature will be based on a calculated temperature value.

Transmission Effects: When the fault is set, calculated temperature is substituted for measured temperature, however the fault code is stored only after three consecutive occurrences of the fault.

Possible Causes:

Temperature sensor
Temperature sensor wiring circuit.
Internal controller

Name Of Code: P0712(7B) - Transmission temperature sensor low

When Monitored: Every 7 milliseconds with the engine running and no loss of prime DTC set.

Set Condition: Sensor output voltage less than 0.078v.

Transmission Effects: When the fault is set, calculated temperature is substituted for measured temperature, however the fault code is stored only after three consecutive occurrences of the fault.

Possible Causes:

Temperature sensor
Temperature sensor wiring circuit.
Internal controller

Name Of Code: P0713(7C) - Transmission temperature sensor high

When Monitored: Every 7 milliseconds with the engine running and no loss of prime DTC set.

Set Condition: Sensor output voltage greater than 4.94v.

Transmission Effects: When the fault is set, calculated temperature is substituted for measured temperature, however the fault code is stored only after three consecutive occurrences of the fault.

Possible Causes:

Temperature sensor
Temperature sensor wiring circuit.
Internal controller

Name Of Code: P0714(7D) - Transmission Temperature Sensor Intermittent

When Monitored: Every 7 milliseconds with the engine running and no loss of prime DTC set.

Set Condition: Temperature reading change greater than maximum change allowed per loop.

Transmission Effects: When the fault is set, calculated temperature is substituted for measured temperature, however the fault code is stored only after three consecutive occurrences of the fault.

Possible Causes:

Temperature sensor
Temperature sensor wiring circuit.
Internal controller