Scan Tool Data List
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT:
Ensure that the scan tool 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. 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 transmission is in PARK or NEUTRAL.
- The accessories are OFF.
- ATC is in 2WD HI.
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 Data List
| Scan Tool Parameter | Data List | Units Displayed | Typical Data Value |
|---|---|---|---|
| 2WD High Indicator Light | Data Display | On/Off | On |
| 4WD High Indicator Light | Data Display | On/Off | Off |
| 4WD Low Active | Data Display | Yes/No | No |
| 4WD Low Indicator Light | Data Display | On/Off | Off |
| Battery Voltage | Data Display | Volts | Battery Voltage |
| Encoder Gear Position | Data Display | 2WD/Neutral/4WD HI/4WD LO | 2WD |
| Encoder Return Voltage | Data Display | Volts | 0-5 V |
| Encoder Supply Voltage | Data Display | Volts | 0-7.5 V |
| Front Axle Requested | Data Display | Yes/No | No |
| Front Axle Switch | Data Display | Locked/Unlocked | Unlocked |
| Ign. Cycles Since Last Current DTC | Data Display | Number | Varies |
| Mode Switch Return Voltage | Data Display | Volts | 0-5 V |
| Mode Switch Selected | Data Display | On/Off | Off |
| Motor A Current | Data Display | mA | Varies |
| Motor B Current | Data Display | mA | Varies |
| Neutral Indicator Light | Data Display | On/Off | Off |
| Service 4WD Lamp | Data Display | On/Off | Off |