The scan tool provides the following capabilities:
| • | Displays the data list |
| • | Displays current and history trouble codes |
| • | Clears the diagnostic trouble codes after a repair is completed |
Important: Ensure that 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.
In order to use the scan tool, connect 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 automatic transfer case (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 diagnostic tables indicate 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:
| • | The engine is at idle. |
| • | The throttle is closed. |
| • | The gear is in PARK or NEUTRAL. |
| • | The 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 Testing for Intermittent Conditions and Poor Connections in wiring systems for further diagnosis.
Scan Tool Parameter | Data List | Units Displayed | Typical Data Value |
|---|---|---|---|
Engine at Idle/Upper Radiator Hose Hot/Closed Throttle/Gear in PARK or NEUTRAL/Accessories OFF | |||
Commanded Mode Indicator | Data Display | 2WD/4WD High/4WD Low | Varies |
Encoder Circuit A | Data Display | On/Off | Off |
Encoder Circuit B | Data Display | On/Off | On |
Encoder Circuit C | Data Display | On/Off | Off |
Encoder Circuit P | Data Display | On/Off | On |
Encoder Gear Position | Data Display | 2WD/4WD High/4WD Low | Varies |
Front Axle Switch | Data Display | Locked/Unlocked | Locked |
Front Axle Switch Requested | Data Display | Yes/No | Yes |
GM Part Number | Data Display | Number | Varies |
Ignition 3 | Data Display | Volts | Battery Voltage |
Mode Switch Selector | Data Display | On/Off | Off |
Neutral Indicator Light | Data Display | On/Off | Off |
Park Switch | Data Display | Closed/Open | Closed |
Service 4WD Lamp | Data Display | On/Off | Off |
Slip Adapt PWM | Data Display | % | 0-100 |
Software ID | Data Display | Number | Varies |
TP Angle | Data Display | % | 0 |
Throttle Anticipation Mode | Data Display | Enabled/Disabled | Disabled |
2WD High Indicator Light | Data Display | On/Off | Off |
4WD High Indicator Light | Data Display | On/Off | Off |
4WD Lamp Open | Data Display | Yes/No | No |
4WD Lamp Shorted | Data Display | Yes/No | No |
4WD Low Indicator Light | Data Display | On/Off | Off |
