Transfer Case Control Module Scan Tool Information
The Transfer Case Shift Control Module Scan Tool Data List contains all transfer case related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.
The values below represent a typical display recorded from a properly functioning system.
IMPORTANT:
Do not use a scan tool that displays faulty data. Report the condition to the scan tool manufacturer. The use of a faulty scan tool can result in misdiagnosis and the unnecessary replacement of parts.
Only the parameters listed below are used/referenced in this manual for diagnosis. If a scan tool displays other parameters, those values are not recommended by General Motors for use in diagnosis.
If all values are within the expected range described below, refer to Symptoms - Transfer Case for diagnosis.
The scan tool values from a properly functioning transfer case may be used for comparison with the transfer case you are diagnosing. The values below represent a typical display recorded from a properly functioning system.
Scan Tool Data Parameters
| Parameter | System State | Expected Value | Description |
|---|---|---|---|
| Operating Conditions: Ignition ON, Engine OFF, transmission in Park or Neutral | |||
| 5 V Reference | 4.8 to 5.2 V | 5.0 V | This parameter displays the voltage being supplied by the transfer case control module to the transfer case fluid temperature sensor. |
| 5 V Reference Circuit Status | Not Run, OK or Malfunction | OK | This parameter monitors the status of the transfer case 5 V reference circuit. An open/high resistance, short to ground or short to voltage on the transfer case 5 V reference circuit will cause this parameter to display Malfunction. |
| Accelerator Pedal Position | 0-100% | 0% | This parameter displays percentage of pedal depression. |
| All Wheel Drive | ON/OFF | OFF | This parameter displays the status of the AWD system. |
| AWD Disabled - Tire Size | Yes/No | No | This parameter displays Yes when a minispare is present. |
| AWD Limited Functionality | Yes/No | No | This parameter displays the status of if the transfer case control module is limiting AWD functionality. |
| Calculated Transfer Case Clutch Temperature | °C (°F) | Varies | This parameter is an estimated value based on engine intake air temperature and transmission fluid temperature. |
| Control Module Voltage Signal | 0.0 to 25.5 V | Battery Voltage | This parameter displays the voltage measured by the transfer case control module at the battery positive voltage circuit. |
| Current Transmission Gear | Park, Reverse, Neutral, 1, 2, 3, 4, 5, and 6 | Park or Neutral | This parameter displays the current gear the transmission is in. |
| Distance Since DTC Cleared | km/h/MPH | 0 | This parameter displays the number of miles driven since the last clearing of DTC's, in km/h or MPH. |
| Ignition 1 Signal | ON/OFF | ON | This parameter displays the status of the ignition 1 signal circuit is seen at the transfer case control module. |
| Ignition Accessory Signal | ON/OFF | ON | This parameter displays the status of the ignition accessory signal circuit is seen at the transfer case control module. |
| Left Front Wheel Speed Sensor | km/h/MPH | 0.00 | This parameter displays the wheel speed in km/h or MPH. |
| Left Rear Wheel Speed Sensor | km/h/MPH | 0.00 | This parameter displays the wheel speed in km/h or MPH. |
| Non-Driven Wheel Speed | km/h/MPH | 0.00 | This parameter displays the wheel speed in km/h or MPH. |
| Overtemperature Protection Mode | Active/Inactive | Inactive | This parameter displays Active when the transfer case control module commands overtemperature protection as based off the transfer case fluid temperature sensor. When commanded active, AWD is disabled. |
| Power Mode | OFF/Accessory/Run/Crank Request | Run | This parameter displays the state of the system power mode. This signal is based upon the state of the system power mode as commanded by the ignition switch. It is received over serial communication from the vehicle electronics. If the serial data signal is not received, the parameter will display OFF. |
| Requested Transfer Case Clutch Torque | Y/lb ft | 0.0 | This parameter displays the amount of clutch torque being requested based on engine torque and accelerator position as well as other inputs. |
| Right Front Wheel Speed Sensor | km/h/MPH | 0.00 | This parameter displays the wheel speed in km/h or MPH. |
| Right Rear Wheel Speed Sensor | km/h/MPH | 0.00 | This parameter displays the wheel speed in km/h or MPH. |
| Service AWD Indicator Command | ON/OFF | OFF | This parameter displays ON if the transfer case control module commands the Service AWD Indicator ON. |
| Steering Wheel Angle | Degrees | Varies | This parameter displays the current position of the steering wheel in degrees. |
| Transfer Case Clutch Command | 0-100% | 0% | This parameter displays the amount of clutch activation being requested, as shown in percentage. |
| Transfer Case Clutch Engagement | 0-100% | 0% | This parameter displays the actual amount of clutch activation achieved, as shown in percentage. |
| Transfer Case Clutch High Control Circuit High Voltage Test Status | Not Run, OK or Malfunction | OK | This parameter monitors the status of the transfer case clutch coil control circuit. A short to voltage on the transfer case clutch coil control circuit will cause this parameter to display Malfunction. |
| Transfer Case Clutch High Control Circuit Low Voltage Test Status | Not Run, OK or Malfunction | OK | This parameter monitors the status of the transfer case clutch coil control circuit. A short to ground on the transfer case clutch coil control circuit will cause this parameter to display Malfunction. |
| Transfer Case Clutch High Control Circuit Open Test Status | Not Run, OK or Malfunction | OK | This parameter monitors the status of the transfer case clutch coil control circuit. An open on the transfer case clutch coil control circuit will cause this parameter to display Malfunction. |
| Transfer Case Clutch High Control Command | ON/OFF | OFF | This parameter displays the requested status of the clutch coil control circuit high side driver. |
| Transfer Case Clutch Low Control Circuit High Voltage Test Status | Not Run, OK or Malfunction | OK | This parameter monitors the status of the transfer case clutch coil return circuit. A short to voltage on the transfer case clutch coil return circuit will cause this parameter to display Malfunction. |
| Transfer Case Clutch Low Control Circuit Low Voltage Test Status | Not Run, OK or Malfunction | OK | This parameter monitors the status of the transfer case clutch coil return circuit. A short to ground on the transfer case clutch coil return circuit will cause this parameter to display Malfunction. |
| Transfer Case Clutch Low Control Circuit Open Test Status | Not Run, OK or Malfunction | OK | This parameter monitors the status of the transfer case clutch coil return circuit. An open on the transfer case clutch coil return circuit will cause this parameter to display Malfunction. |
| Transfer Case Clutch Low Control Command | ON/OFF | OFF | This parameter displays the requested status of the clutch coil return circuit low side driver. |
| Transfer Case Clutch Overtemperature Counter | Counts | 0 | This parameter displays the number of clutch overtemps that have occurred. |
| Transfer Case Clutch Torque | Y/lb ft | 0.0 | This parameter displays the amount of torque in Y/lb ft. |
| Transfer Case Fluid Temperature Sensor | °C (°F) | Varies | This parameter displays the transmission fluid temperature in degrees Celsius or Fahrenheit. |
| Transfer Case Output Shafts Slip Speed | RPM | 0 | This parameter displays the difference between the rotational speeds of the transfer case output shafts. |
| Transmission Fluid Temperature | °C (°F) | Varies | This parameter displays the transmission fluid temperature in degrees Celsius or Fahrenheit. |
| Vehicle Stability Control Request | % | 0 | This parameter displays the amount of AWD modification requested by the vehicle electronic stability system. |
| Warm-Ups Since DTC Cleared | Counts | Varies | This parameter indicates the number of warm-up cycles that have occurred since DTCs were cleared. |
| Warm-Ups without Non-Emission Malfunctions | Counts | Varies | This parameter displays the number of OBD defined warm-up cycles since the last non-emissions related (fault type C) fail report. Non-emissions related DTCs are cleared from memory when this counter reaches 40. |
Scan Tool Output Controls
| Output Control | Description |
|---|---|
| Refer to the scan tool manual for complete scan tool operating instructions. | |
| Transfer Case Clutch | This function allows the technician to command the clutch coil to be energized from 0-100 percent PWM. |
| Transfer Case Clutch Engagement | This function allows the technician to command the clutch coil high side and low side drivers ON or OFF. |
| Transfer Case Clutch Identifier (Configuration/Reset) | This function allows the technician to reset the transfer case clutch coil identifier. |
| Transfer Case Clutch Overtemp Counter Reset | This function allows the technician to command the over temperature counter to be zeroed. |