Conditions for Setting the DTC

A certain number of no valid transmitted messages on the GMLAN serial data circuits are detected by the module. The engine will not start when there is a total malfunction of the high speed GMLAN serial data circuits while the engine is not running. The following conditions may cause a total loss of high speed GMLAN data communication:

• A short between high speed GMLAN (+) and high speed GMLAN (-) circuits
• Any of the high speed GMLAN serial data circuits shorted to ground or voltage
• A module internal malfunction that causes a short to voltage or ground on the high speed GMLAN circuits
• Any of the high speed GMLAN serial data circuits open