LEMON Manuals: Even more car manuals for everyone
Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 231 (Transfer Case - Mp 3023/3024-NQH) >> Diagnostic Information and Procedures >> DTC P279A >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
  1. 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.
    • If the scan tool display does not match the transfer case range switch state, repair the transfer case system. Refer to Diagnostic Starting Point - Transfer Case .
    • If the scan tool matches the transfer case range switch state, continue with testing.
  2. Program the ECM with the latest software version and retest for DTCs.
    • If the DTC resets, replace the ECM.
scientia non olet · About LEMON Manuals