Instrument Panel Cluster (IPC) and Engine Control Module (ECM) Functionality

WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

If all circuits referenced above check good use the scan tool under engine data 2 to see if the scan tool still indicates the vehicle is still in 4WD.

If the scan tool indicates the vehicle is in 4WD then replace the engine control module, if not then replace the IPC.