Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Chevrolet Tahoe, 2007 Chevrolet Suburban, and 2007 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- With the ignition OFF, disconnect the harness connector at the EBCM, ESC module, and DSCC module one at a time. After each disconnect, clear the DTC, cycle the ignition key 3 times, then retest for the DTC. DTC U2099 should reset.
- If the DTC does not reset, replace the last module disconnected.
- Ignition OFF, disconnect the harness connector at the BCM.
- With all modules disconnected, test for infinite resistance between the high speed GMLAN serial data wake up circuit and ground.
- If less than infinite resistance, repair the wake up circuit for a short to ground.
- If all tests normal and DTC is current, replace the BCM.