Diagnostic Aids

WARNING: This page is about a different car, the 2002 Pontiac Grand Prix. However, it is still accessible from the selected car via links, so may be relevant.

An open in the ignition 1 circuit to the PCM will cause the PCM to stop communicating without setting communication DTCs. Refer to CIRCUIT TESTING and WIRING REPAIRS .
If a short to B+ was present, a history U1301 or U1305 will set in the modules. Refer to DTC U1300, U1301, or U1305 (Generic Short DTC) .
If a short to ground was present, a history U1300 or U1305 will set in the modules. Refer to DTC U1300, U1301, or U1305 (Generic Short DTC) .
Disconnecting modules and turning the ignition switch to RUN may cause DTCs in these modules. Check for DTCs in each module upon completion of the required repair.