Engine Controls - Diagnostics: Pre-Check

DIAGNOSIS SYSTEM

Description
- When troubleshooting OBD II vehicles, the only difference from the usual troubleshooting procedure is that you need to connect the vehicle to the OBD II scan tool complying with SAE J1978 or the hand held tester, and read various data output from the vehicle's ECM.
  
  Fig 1: Identifying Check Diagnosis System
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- OBD II regulations require that the vehicle's on board computer illuminates the Malfunction Indicator Light (MIL) on the instrument panel when the computer detects a malfunction in the emission control system/components or in the powertrain control components which affect vehicle emissions, or a malfunction in the computer. In addition to the MIL illuminating when a malfunction is detected, the applicable Diagnostic Trouble Codes (DTCs) prescribed by SAE J2012 are recorded in the ECM memory (See PRE-CHECK ).
  If the malfunction does not reoccur in 3 consecutive trips, the MIL goes off automatically but the DTCs remain recorded in the ECM memory.
- To check the DTC, connect the hand-held tester or OBD II scan tool to the Data Link Connector 3 (DLC3) on the vehicle. The hand-held tester or OBD II scan tool also enables you to erase the DTC and check the freeze frame data and various forms of engine data (for operating instructions, see the OBD II scan tool's instruction book.). The DTC includes SAE controlled codes and manufacturer controlled codes. SAE controlled codes must be set as prescribed by the SAE, while manufacturer controlled codes can be set freely by a manufacturer within the prescribed limits (see the DTC CHART ).
  
  Fig 2: Connecting Hand-Held Tester Or OBD II Scan Tool To Data Link Connector
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- The diagnosis system operates in the normal mode during normal vehicle use. It also has a check mode for technicians to simulate malfunction symptoms and troubleshoot them. Most DTCs use the 2 trip detection logic* to prevent erroneous detection, and to ensure a thorough malfunction detection. By switching the ECM to the check mode when troubleshooting, a technician can cause the MIL to illuminate for a malfunction that is only detected once or momentarily (hand-held tester only) (See step 3).
- *2 trip detection logic:
  When a malfunction is first detected, the malfunction is temporarily stored in the ECM memory (1st trip). If the same malfunction is detected again during the second drive test, this second detection causes the MIL to illuminate (2nd trip) (However, the ignition switch must be turned OFF between the 1st trip and 2nd trip.)
- Freeze frame data:
  The freeze frame data records the engine conditions (fuel system, calculated load, engine coolant temperature, fuel trim, engine speed, vehicle speed, etc.) when the malfunction is detected. When troubleshooting, it is useful to determine whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time the malfunction occurred.
Priorities for troubleshooting:

If troubleshooting priorities for multiple DTCs are given in the applicable DTC chart, these priorities should be followed.

If no instructions are given, perform troubleshooting for those DTCs according to the following priorities.
1. DTCs other than fuel trim malfunction (DTC P0171, P0172) and misfire (DTC P0300 - P0304).
2. Fuel trim malfunction (DTC P0171, P0172).
3. Misfire (DTC P0300 - P0304).

Check the DLC3.

The vehicle's ECM uses the ISO 9141-2 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 9141-2 format.

Fig 3: Identifying DLC3 Connector Terminal

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

TERMINAL SYMBOL

Symbol	Name	Result
(Terminal No.)	(Reference terminal)	(Condition)
SIL	Bus "+" line	Pulse generation
(7)	(5 - Signal ground)	(During transmission)
CG	Chassis ground	1 Ω or less
(4)	(Body ground)	(Always)
SG	Signal ground	1 Ω or less
(5)	(Body ground)	(Always)
BAT	Battery positive	9 to 14 V
(16)	(Body around)	(Always)

HINT:

If the display shows UNABLE TO CONNECT TO VEHICLE when you have connected the cable of the OBD II scan tool or the hand-held tester to the DLC3, turned the ignition switch ON and operated the scan tool, there is a problem on the vehicle side or tool side.

If the communication is normal when the tool is connected to another vehicle, inspect the DLC3 on the original vehicle.
If communication is still impossible when the tool is connected to another vehicle, the problem is probably in the tool itself, so consult the Service Department listed in the tool's instruction manual.

Inspect the battery voltage.
Battery Voltage: 11 to 14 V

If voltage is below 11 V, recharge the battery before proceeding.

Fig 4: Checking MIL Diagnosis System
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Check the MIL.
1. The MIL comes on when the ignition switch is turned ON and the engine is not running.
  HINT:
  
  If the MIL is not illuminated, troubleshoot the MIL circuit (See MIL CIRCUIT ).
2. When the engine is started, the MIL should go off.
  If the lamp remains on, it means that the diagnosis system has detected a malfunction or abnormality in the system.

DTC CHECK (Normal Mode)
NOTE:
- If there is no DTC in the normal mode, check the pending fault code using the Continuous Test Results function (Mode 7 for SAE J1979) on the OBD II scan tool or the hand-held tester.
- Hand-held tester only: When the diagnosis system is switched from the normal mode to the check mode, all the DTCs and freeze frame data recorded in the normal mode will be erased. So before switching modes, always check the DTCs and freeze frame data, and then write them down.
1. Checking DTCs using the OBD II scan tool or hand-held tester.
  1. Connect the OBD II scan tool or the hand-held tester to the DLC3.
  2. Turn the ignition switch ON.
  3. Use the OBD II scan tool or the hand-held tester to check the DTCs and freeze frame data and then write them down. If you need help with the OBD II scan tool, refer to the scan tool's instruction book.
    If there is no DTC in the normal mode, check the pending fault code using the Continuous Test Results function (Mode 7 for SAE J1979) on the OBD II scan tool or the hand-held tester.
    
    Fig 5: Connecting OBD II Scan Tool Or Hand-Held Tester To DLC3
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. See DIAGNOSTIC TROUBLE CODE CHART to confirm the details of the DTCs.
  NOTE:
  - When simulating a symptom with the OBD II scan tool (excluding hand-held tester) to check the DTCs, use the normal mode. For code on the DTC chart subject to "2 trip detection logic", perform either of the following actions.
  - Turn the ignition switch OFF after the symptom is simulated once. Then repeat the simulation process again. When the problem has been simulated twice, the MIL lights up and the DTCs are recorded in the ECM.
  - Check the pending fault code using the Continuous Test Results function (Mode 7 for SAE J1979) on the OBD II scan tool.
2. Clearing the DTCs using the OBD II scan tool or the hand-held tester.
  1. Connect the OBD II scan tool or the hand-held tester to the DLC3.
  2. Turn the ignition switch ON.
  3. When operating the OBD II scan tool (complying with SAE J1978) or the hand-held tester to erase the codes, the DTCs and freeze frame data will be erased. (See the OBD II scan tool's instruction book for operating instructions.)
3. Clearing the DTCs not using the OBD II scan tool or the hand-held tester.
  1. Disconnect the battery terminal or remove the EFI fuse from the engine room J/B for more than 60 seconds.
DTC CHECK (Check Mode)
HINT:

Hand-held tester only:

Compared to the normal mode, the check mode has more sensing ability to detect malfunctions. Furthermore, the same diagnostic items which are detected in the normal mode can also be detected in the check mode.
1. Procedure for Check Mode using the hand-held tester.
  1. Check the initial conditions
    - Battery positive voltage 11 V or more.
    - Throttle valve fully closed.
    - Transmission in the P or N position.
    - A/C switched OFF.
  2. Turn the ignition switch OFF.
  3. Connect the hand-held tester to the DLC3.
  4. Turn the ignition switch ON.
    
    Fig 6: Connecting Hand-Held Tester To DLC3
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. Switch the hand-held tester from the normal mode to the check mode (check that the MIL flashes.).
    NOTE: If the hand-held tester switches the ECM from the normal mode to the check mode or vise-versa, or if the ignition switch is turned from ON to ACC or OFF during the check mode, the DTC and freeze frame data will be erased.
  6. Start the engine (MIL goes off after the engine is started.).
    
    Fig 7: Checking That MIL Flashes Blinking Pattern
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. Simulate the conditions of the malfunction described by the customer.
    NOTE: Leave the ignition switch ON until you have checked the DTC, etc.
  8. After simulating the malfunction conditions, use the hand-held tester diagnosis selector to check the DTCs and freeze frame data, etc.
    HINT:
    
    Be sure not to turn the ignition switch OFF, as turning it OFF switches the diagnosis system from the check mode to the normal mode, which erases all the DTCs, etc.
  9. After checking the DTC, inspect the applicable circuit.
2. Clearing the DTCs using the OBD II scan tool or the hand-held tester.
  1. Connect the OBD II scan tool or the hand-held tester to the DLC3.
  2. Turn the ignition switch ON.
  3. When operating the OBD II scan tool (complying with SAE J1978) or the hand-held tester to erase the codes, the DTCs and freeze frame data will be erased. (Seethe OBD II scan tool's instruction book for operating instructions.)
3. Clearing the DTCs not using the OBD II scan tool or the hand-held tester.
  1. Disconnect the battery terminal or remove the EFI fuse from the engine room J/B for more than 60 seconds.

FAIL-SAFE CHART

If any of the following codes is recorded, the ECM enters the fail-safe mode.

FAIL-SAFE CHART

DTC No.	Fail-Safe Operation	Fail-Safe Deactivation Conditions
P0031	The heater circuit in which the abnormality is detected is turned off	Ignition switch OFF
P0032	The heater circuit in which the abnormality is detected is turned off	Ignition switch OFF
P0037	The heater circuit in which the abnormality is detected is turned off	Ignition switch OFF
P0038	The heater circuit in which the abnormality is detected is turned off	Ignition switch OFF
P0100	Ignition timing is calculated from engine speed and a throttle angle	"Pass" condition detected.
P0102	Ignition timing is calculated from engine speed and a throttle angle	"Pass" condition detected.
P0103	Ignition timing is calculated from engine speed and a throttle angle	"Pass" condition detected.
P0110	Intake air temp. is fixed at 20°C (68°F)	"Pass" condition detected.
P0112	Intake air temp. is fixed at 20°C (68°F)	"Pass" condition detected.
P0113	Intake air temp. is fixed at 20°C (68°F)	"Pass" condition detected.
P0115	Engine coolant temp. is fixed at 80°C (176°F)	"Pass" condition detected.
P0117	Engine coolant temp. is fixed at 80°C (176°F)	"Pass" condition detected.
P0118	Engine coolant temp. is fixed at 80°C (176°F)	"Pass" condition detected.
P0120	Fuel cut intermittently	"Pass" condition detected and ignition switch OFF
P0122	Fuel cut intermittently	"Pass" condition detected and ignition switch OFF
P0123	Fuel cut intermittently	"Pass" condition detected and ignition switch OFF
P0121	Fuel cut intermittently	"Pass" condition detected and ignition switch OFF
P0325	Max. ignition timing retardation	Ignition switch OFF
P0351	Fuel cut	"Pass" condition detected.
P0352	Fuel cut	"Pass" condition detected.
P0353	Fuel cut	"Pass" condition detected.
P0354	Fuel cut	"Pass" condition detected.

CHECK FOR INTERMITTENT PROBLEMS
Hand-held tester only:

By putting the vehicle's ECM in the check mode, the 1 trip detection logic is possible instead of the 2 trip detection logic, and the sensitivity to detect faults is increased. This makes it easier to detect intermittent problems.
1. Clear the DTCs. (See step 2)
2. Set the check mode. (See step 3)
3. Perform a simulation test (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
4. Check the connector and terminal (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
5. Wiggle the harness and connector (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
BASIC INSPECTION
When the malfunction is not confirmed in the DTC check, troubleshooting should be carried out in all the possible circuits considered as causes of the problem. In many cases, by carrying out the basic engine check shown in the following flow chart, the location causing the problem can be found quickly and efficiently. Therefore, using this check is essential in the engine troubleshooting.
1. Is battery positive voltage 11 V or more when engine stopped?
  NO: Charge or replace battery.
  
  YES: Go to next step.
2. Is engine cranked?
  NO: Proceed to STARTER .
  
  YES: Go to next step.
3. Does engine start?
  NO: Go to step 7 .
  
  YES: Go to next step.
4. Check air filter.
  PREPARATION:
  
  Remove the air filter.
  
  CHECK:
  
  Visually check that the air filter is not excessively dirty or oily.
  
  NG: Repair or replace air filter.
  
  OK: Go to next step.
5. Check idle speed.
  PREPARATION:
  1. Warm up the engine to the normal operating temperature.
  2. Switch off all the accessories.
  3. Switch off the A/C.
  4. Shift the transmission into the N position.
  5. Connect the OBD II scan tool or hand-held tester to the DLC3 of the vehicle.
  CHECK:
  
  Use CURRENT DATA to check the idle speed.
  
  OK:
  
  Idle speed:
  
  M/T 600 to 700 RPM
  
  A/T 650 to 750 RPM
  
  NG: Proceed to PROBLEM SYMPTOMS TABLE .
  
  OK: Go to next step.
6. Check ignition timing.
  PREPARATION:
  1. Warm up the engine to the normal operating temperature.
  2. Shift the transmission into the N position.
  3. Keep the engine speed at idle.
  4. Using SST, connect terminals 13 (TC) and 4 (CG) of the DLC3.
    SST 09843-18040
  5. Connect the timing light.
  CHECK:
  
  Check the ignition timing.
  
  OK:
  
  Ignition timing:
  
  8 to 12° BTDC at idle
  
  Fig 8: Checking Ignition Timing
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  NG: Proceed to ON-VEHICLE INSPECTION and continue to troubleshoot.
  
  OK: Proceed to PROBLEM SYMPTOMS TABLE .
7. Check fuel pressure.
  PREPARATION:
  1. Be sure that enough fuel is in the tank.
  2. Connect the hand-held tester to the DLC3.
  3. Turn the ignition switch ON and push the hand-held tester main switch ON.
  4. Use ACTIVE TEST mode to operate the fuel pump.
  5. Please refer to the hand-held tester operator's manual for further details .
  6. If you have no hand-held tester, connect the positive (+) and negative (-) battery leads to the fuel pump connector (See ON-VEHICLE INSPECTION ).
    
    Fig 9: Checking Fuel Pressure
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  CHECK:
  
  Check for the fuel pressure in the fuel inlet hose when it is pinched by hand.
  
  HINT:
  
  At this time, you will hear a fuel flowing sound.
  
  NG: Proceed to ON-VEHICLE INSPECTION and continue to troubleshoot.
  
  OK: Go to next step.
8. Check for spark.
  PREPARATION:
  1. Disconnect the ignition coil.
  2. Remove the spark plug.
  3. Install the spark plug to the ignition coil assembly.
  4. Disconnect the injector connector.
  5. Ground the spark plug.
  CHECK:
  
  Check if spark occurs while the engine is being cranked.
  NOTE:
  - Do not crash the electrode gap.
  - To prevent the injectors from injecting excess fuel during this test, do not crank the engine for more than 5 seconds at one time.
  NG: Proceed to ON-VEHICLE INSPECTION and continue to troubleshoot.
  
  OK: Proceed to PROBLEM SYMPTOMS TABLE .
DATA LIST
HINT:

Using the DATA LIST displayed by the hand-held tester or the OBD II scan tool, you can read the values of the switches, sensors, actuators and so on without parts removal. Reading the DATA LIST as the first step of troubleshooting is one method to shorten diagnostic time.

NOTE: The values given below for "Normal Condition" are representative values. A vehicle may still be normal even if its value differs from those listed here. Do not solely depend on the "Normal Condition" here when deciding whether a part is faulty or not.
1. Warm up the engine.
2. Turn the ignition switch OFF.
3. Connect the hand-held tester or the OBD II scan tool to the DLC3.
4. Turn the ignition switch ON.
5. Push the "ON" button of the hand-held tester or the OBD II scan tool.
6. Select the item "DIAGNOSIS/ENHANCED OBD II/DATA LIST".
7. According to the display on tester, read the "DATA LIST".
Fig 10: Identifying Data List (1 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 11: Identifying Data List (2 Of 2)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
ACTIVE TEST
HINT:

Performing the ACTIVE TEST using the hand-held tester or the OBD II scan tool allows the relay, VSV, actuator and so on to operate without parts removal. Performing the ACTIVE TEST as the first step of troubleshooting is one method to shorten diagnostic time.

It is possible to display the DATA LIST during the ACTIVE TEST.
1. Warm up the engine.
2. Turn the ignition switch OFF.
3. Connect the hand-held tester or the OBD II scan tool to the DLC3.
4. Turn the ignition switch ON.
5. Push the "ON" button of the hand-held tester or the OBD II scan tool.
6. Select the item "DIAGNOSIS/ENHANCED OBD II/ACTIVE TEST".
7. According to the display on tester, perform the "ACTIVE TEST".
  
  Fig 12: Identifying Active Test Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DEFINITION OF TERMS

Term	Definition
Monitor description	Description of what the ECM monitors and how it detects malfunctions (monitoring purpose and its details).
Related DTCs	Diagnostic code
Typical enabling condition	Preconditions that allow the ECM to detect malfunctions.
Typical enabling condition	With all preconditions satisfied, the ECM sets the DTC when the monitored value(s) exceeds the malfunction threshold(s).
Sequence of operation	The priority order that is applied to monitoring, if multiple sensors and components are used to detect the malfunction.
Sequence of operation	While another sensor is being monitored, the next sensor or component will not be monitored until the previous monitoring has concluded.
Required sensor/components	The sensors and components that are used by the ECM to detect malfunctions.
Frequency of operation	The number of times that the ECM checks for malfunctions per driving cycle.
Frequency of operation	"Once per driving cycle" means that the ECM detects malfunction only one time during a single driving cycle.
Frequency of operation	"Continuous" means that the ECM detects malfunction every time when enabling condition is met.
Duration	The minimum time that the ECM must sense a continuous deviation in the monitored value(s) before setting a DTC. This timing begins after the "typical enabling conditions" are met.
Malfunction thresholds	Beyond this value, the ECM will conclude that there is a malfunction and set a DTC.
MIL operation	MIL illumination timing after a defect is detected.
MIL operation	"Immediately" means that the ECM illuminates MIL, the instant the ECM determines that there is a malfunction.
MIL operation	"2 driving cycle" means that the ECM illuminates MIL, if the same malfunction is detected again in the 2nd driving cycle.

TOYOTA/LEXUS PART AND SYSTEM NAME LIST

This reference list indicates the part names used in this manual along with their definitions.

TOYOTA/LEXUS PART AND SYSTEM NAME LIST

TOYOTA/LEXUS name	Definition
Toyota HCAC system, Hydro-carbon Adsorptive Catalyst (HCAC) system, HC adsorptive three-way catalyst	HC adsorptive three-way catalytic converter
Variable Valve Timing sensor, VVT sensor	Camshaft position sensor
Variable valve timing system, VVT system	Camshaft timing control system
Camshaft timing oil control valve, Oil control valve, OCV, VVT, VSV	Camshaft timing oil control valve
Variable timing and lift, VVTL	Camshaft timing and lift control
Crankshaft position sensor "A"	Crankshaft position sensor
Engine speed sensor	Crankshaft position sensor
THA	Intake air temperature
Knock control module	Engine knock control module
Knock sensor	Engine knock sensor
Mass or volume air flow circuit	Mass air flow sensor circuit
Vacuum sensor	Manifold air pressure sensor
Internal control module, Control module, Engine control ECU, PCM	Power train control module
FC idle	Deceleration fuel cut
Idle air control valve	Idle speed control
VSV for CCV, Canister close valve VSV for canister control	Evaporative emissions canister vent valve
VSV for EVAP, Vacuum switching valve assembly No. 1, EVAP VSV, Purge VSV	Evaporative emissions canister purge valve
VSV for pressure switching valve, Bypass VSV	Evaporative emission pressure switching valve
Vapor pressure sensor, EVAP pressure sensor, Evaporative emission control system pressure sensor	Fuel tank pressure sensor
Charcoal canister	Evaporative emissions canister
ORVR system	On-board refueling vapor recovery system
Intake manifold runner control	Intake manifold tuning system
Intake manifold runner valve, IMRV, IACV (runner valve)	Intake manifold tuning valve
Intake control VSV	Intake manifold tuning solenoid valve
AFS	Air fuel ratio sensor
O2 sensor	Heater oxygen sensor
Oxygen sensor pumping current circuit	Oxygen sensor output signal
Oxygen sensor reference ground circuit	Oxygen sensor signal ground
Accel position sensor	Accelerator pedal position sensor
Throttle actuator control motor, Actuator control motor, Electronic throttle motor, Throttle control motor	Electronic throttle actuator
Electronic throttle control system, Throttle actuator control system	Electronic throttle control system
Throttle/pedal position sensor, Throttle/pedal position switch, Throttle position sensor/switch	Throttle position sensor
Turbo press sensor	Turbocharger pressure sensor
Turbo VSV	Turbocharger pressure control solenoid valve
P/S pressure switch	Power-steering pressure switch
VSV for ACM	Active control engine mount
Speed sensor, Vehicle speed sensor "A", Speed sensor for skid control ECU	Vehicle speed sensor
ATF temperature sensor, Trans. fluid temp. sensor, ATF temperature sensor "A"	Transmission fluid temperature sensor
Electronic controlled automatic transmission, ECT	Electronically controlled automatic
Intermediate shaft speed sensor "A"	Counter gear speed sensor
Output speed sensor	Output shaft speed sensor
Input speed sensor, Input turbine speed sensor "A", Speed sensor (NT), Turbine speed sensor	Input turbine speed sensor
PNP switch, NSW	Park/neutral position switch
Pressure control solenoid	Transmission pressure control solenoid
Shift solenoid	Transmission shift solenoid valve
Transmission control switch, Shift lock control unit	Shift lock control module
Engine immobilizer system, Immobilizer system	Vehicle anti-theft system

List of Disable a Monitor
HINT:

This table indicates ECM monitoring status for the items in the upper columns if the DTCs in each line on the left are being set.

Fig 13: Identifying ECM Monitoring Status (1 Of 4)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 14: Identifying ECM Monitoring Status (2 Of 4)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 15: Identifying ECM Monitoring Status (3 Of 4)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 16: Identifying ECM Monitoring Status (4 Of 4)
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
CHECKING MONITOR STATUS
1. INTRODUCTION
  The purpose of the monitor result (mode 6) is to allow access to the results for on-board diagnostic monitoring tests of specific components/systems that are not continuously monitored. Examples are catalyst, EVAP and thermostat.
  
  The monitor result allows the OBD scan tool to display the monitor status, test value and test limit. The monitor status indicates whether the component is functioning normally or not (PASS or FAIL). The test value is the value that was used to determine the monitor status. When the test value is inside the test limit, the ECM determines the component is functioning normally (PASS). If the test value is outside the test limit, the ECM determines the component is malfunctioning (FAIL).
  
  A problem in these components/systems can be found by comparing the test value and test limit. The monitor result information is included under "MONITOR RESULT" in the DTC sections.
2. PROCEDURE
  NOTE: The monitor result and test value are cleared when the ignition switch is turned OFF.
  1. Connect the hand-held tester to the DLC3.
  2. Turn the ignition switch ON.
  3. Clear the DTCs.
  4. Run the vehicle in accordance with the applicable drive pattern described in READINESS MONITOR DRIVE PATTERN (see READINESS MONITOR DRIVE PATTERN ).
  5. Select from the tester menus: DIAGNOSIS, ENHANCED OBD II, MONITOR INFO and MONITOR RESULT. The monitor result appears after the component name.
    INCMP: The component has not been monitored yet.
    
    PASS: The component is functioning normally.
    
    FAIL: The component is malfunctioning.
  6. Confirm that the component is set to either PASS or FAIL.
    
    Fig 17: Displaying Monitor Result
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  7. Select the component (Label) and press ENTER.
    The accuracy test value appears when the monitor result is either PASS or FAIL.
    
    VAL The test value
    
    LMT: The test limit
    
    TLT: The test limit type. Either 0 or 1 is displayed.
  8. If TLT is 0, the component is malfunctioning when the test value is higher than the test limit. If TLT is 1, the component is malfunctioning when the test value is lower than the test limit.
    
    Fig 18: Displaying Thermostat Malfunction
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  9. Compare the test value with the test limit. The test value is usually significantly higher or lower than the test limit. If the test value is on the borderline of the test limit, there is a potential malfunction in the component.
  HINT:
  
  The monitor result might on rare occasions be PASS even if the MIL is illuminated. This indicates the system malfunctioned on a previous driving cycle. This might be caused by an intermittent problem.