Circuit/System Testing

WARNING: This page is about a different car, the 2008 GMC Yukon and 2008 Chevrolet Tahoe. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: Diagnose and repair any communication DTCs prior to performing this testing.

Program the engine control module (ECM) with the latest software version and recheck for DTCs.

If the DTC resets after programming or if the ECM already contains the latest software version, replace the ECM.