Circuit/System Testing
NOTE:
You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Ignition ON, observe the Ignition 1 Signal and the EC Ignition Relay Feedback scan tool parameter to determine which is more than 3 V lower than the other.
- Ignition OFF, if the EC Ignition Relay Feedback parameter is more than 3 V lower, remove the powertrain relay. If the Ignition 1 Signal parameter is more than 3 V lower, remove the ECM IGN fuse.
- Ignition ON, connect a 20 A fused jumper wire between B+ and the applicable ignition voltage circuit terminal leading to the ECM. Verify that the applicable scan tool parameter displays between 9-14 V.
- If the applicable scan tool parameter is less than the specified value, test the ignition voltage circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- If all circuits test normal, replace the applicable relay.
NOTE:
The Ignition 1 Signal is supplied by the ignition main relay. The ignition main relay is part of the underhood fuse block and is not serviced separately. The EC Ignition Relay Feedback signal is supplied by the powertrain relay.
NOTE:
A resistance of 6 Ω or greater in the circuit/underhood fuse block will cause the DTC to set.