Circuit/System Verification
- If DTCs P0685 or P0690 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 2 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.