The scan tool provides the following capabilities:
| • | Displays the data list. |
| • | Displays current and history trouble codes. |
| • | Clear the diagnostic trouble codes after a repair is completed. |
Important: Make sure the scan tool that you are using is functioning properly and has the latest software. Use of a malfunctioning scan tool or one that has old software can result in misdiagnosis and unnecessary parts replacement.
To use the scan tool, connect it to the Data Link Connector (DLC) and turn the ignition switch to the RUN position.
The Transfer Case Scan Tool Data List contains all the ATC related parameters that are available on the scan tool. The scan tool data list is arranged in alphanumeric order.
Use the Transfer Case Scan Tool Data List only after the following is determined:
| • | A Diagnostic System Check has been completed. |
| • | No Diagnostic Trouble Codes (DTCs) are set. |
| • | Transfer Case Diagnostics indicates the system is functioning properly. |
Scan tool values from a properly operating system may be used for comparison with the transfer case system you are diagnosing. The Transfer Case Scan Tool Data List represents values recorded under the following conditions:
| • | Engine is at idle |
| • | Closed throttle |
| • | Gear is in PARK or NEUTRAL |
| • | Accessories are OFF |
Only the parameters listed below are referenced in this service manual for use in diagnosis. If all values are within the typical range described below, refer to Intermittence and Poor Connections for further diagnosis.
Engine is at Idle, Upper Radiator Hose Hot, Closed Throttle, Gear is in Park or Neutral, and Accessories are OFF. | ||
|---|---|---|
Scan Tool Parameter | Units Displayed | Typical Data Value |
ATC Slip Speed | rpm | 0 |
Auto 4WD Indicator Light | On/Off | On |
Commander Mode Indicated | 2WD/4WD High/4WD Low/Auto 4WD | Varies |
Encoder Circuit A | On/Off | Off |
Encoder Circuit B | On/Off | On |
Encoder Circuit C | On/Off | Off |
Encoder Circuit P | On/Off | On |
Encoder Gear Position | 2WD/4WD High/4WD Low/Auto 4WD | Varies |
Front Axle Switch | Locked/Unlocked | Locked |
Front Axle Switch Requested | Yes/No | Yes |
Front Propshaft Speed | rpm | 0 |
GM Part Number | Number | Varies |
Ignition 3 | Volts | Battery Voltage |
Last Adapt Highest PWM | %DC | 0 |
Mode Switch Selector | On/Off | Off |
Neutral Indicator Light | On/Off | Off |
Park Switch | Closed/Open | Closed |
Rear Propshaft Speed | rpm | 0 |
Rear Slippage | rpm | 0 |
Service 4WD Lamp | On/Off | Off |
Slip Adapt Mode | Enabled/Disabled | Disabled |
Slip Adapt PWM | %DC | 0 |
Software ID | Number | Varies |
TP Angle | % | 0 |
Throttle Anticipation Mode | Enabled/Disabled | Disabled |
Transfer Case Lock | Enabled/Disabled | Enabled |
2WD High Indicator Light | On/Off | Off |
4WD High Indicator Light | On/Off | Off |
4WD Lamp Open | Yes/No | No |
4WD Lamp Shorted | Yes/No | No |
4WD Low Indicator Light | On/Off | Off |
