Circuit/System Verification
- 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.