Circuit/System Testing
WARNING: This page is about a different car, the 2008 GMC Sierra, 2008 GMC Cab & Chassis Sierra, 2008 Chevrolet Silverado, and 2008 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- With the ignition OFF, disconnect the X 1 harness connector at the EBCM, DSCC, and ESC module one at a time. After each disconnect, retest for current DTCs. DTC U2099 should remain current.
- If the DTC becomes history, replace the module disconnected before the DTC became history.
- Ignition OFF, disconnect the harness connector X 3 at the BCM.
- With the X 1 harness connector at the EBCM, DSCC, and ESC modules disconnected, test for infinite resistance between the high speed GMLAN serial data wake up circuit terminal 19 and ground.
- If less than the specified value, test the wake up circuit for a short to ground.
- If all circuits test normal and DTC is current, replace the BCM.