Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.

Observe the 4WD Signal in the ECM Data List. The 4WD signal should display Enabled when you shift into 4WD and Disabled when you shift into 2WD or neutral.
- If the scan tool display does not match the transfer case range switch state, repair the transfer case system. Refer to Diagnostic System Check - Vehicle (with HP2) , Diagnostic System Check - Vehicle (without HP2) .
- If the scan tool matches the transfer case range switch state, continue with testing.
Program the ECM with the latest software version and retest for DTCs.
- If the DTC resets, replace the ECM.