Circuit/System Verification
WARNING: This page is about a different car, the 2008 Pontiac G5 and 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
- If DTCs P0685, P0689, P0690, or B1380 are set, diagnose those DTCs first.
- Ignition ON, engine OFF, observe the Ignition 1 voltage signal, and the EC Ignition Relay Feedback signal parameters, on the scan tool. Both parameter values should display no more than 3 volts difference, between the two parameters.
- Ignition OFF, observe the ignition 1 voltage signal parameter, on the scan tool. The parameter value should be 0 volts, before the ECM powers down.