Loss Of Communication Stability Lamp On With Multiple U-Code DTCs - keywords communication DTC EBCM ECM LAT LE5 nocomm stabilitrak stability U2106 U2107 U2105 U2143 U1899 U1886 U1863

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

On rare occasions, a technician may comment of various electrical concerns including but not limited to: ABS Lamp on, IP-Gauges inop, SRS/SIR light and/or various GMLAN Communication DTC's (multiple U-codes) in one or more modules setting in the vehicle. The following may help to locate the source of these concerns.

This may be caused by a short to ground of the vehicle wiring (such as GMLAN Circuit #2500) in the engine harness. The harness may be chaffed in the area of the Canister Purge Solenoid attachment bracket, causing an intermittent shorting to ground. The Engine harness routing forces the harness into the sharp edge of the bracket. (See Attached picture) The Purge Solenoid bracket has a sharp edge from the shearing operation.

Repair any wiring found to be suspect. To prevent future chaffing remove the sharp edge from the purge solenoid bracket and add conduit to the engine harness at the ECM and Purge Solenoid harness breakouts.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.