Diagnostic Aids

WARNING: This page is about a different car, the 2008 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

Use the DMM MIN/MAX function to capture/locate intermittent conditions.
Short to voltage in the run/crank relay coil control circuit will cause the malfunction indicator lamp (MIL) to illuminate with the ignition key OFF, and the engine will remain running if started and the ignition key is removed.