Circuit/System Testing
- Ignition ON, observe the Ignition 1 Signal and EC Ignition Relay Feedback scan tool parameters to determine which is less than B+.
- Ignition OFF, remove the relay that corresponds to the scan tool parameter that is less than B+.
- Ignition ON, connect a 3A fused jumper wire between B+ and the applicable ignition 1 circuit terminal. Verify that the applicable scan tool parameter displays B+.
- If the applicable scan tool parameter is less than the specified value, test the ignition 1 circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
- Ignition OFF, ensure the ECM is powered down. Measure for battery voltage between the relay armature supply circuit and ground. There should be no voltage present.
- If voltage is present test each control circuit for the components which are supplied by the powertrain relay for a short to B+.
- If all circuits test normal, test or replace the applicable relay/underhood fuse block.
IMPORTANT:
Six ohms or greater in the circuit/underhood fuse block will cause the DTC to set.
IMPORTANT:
A short to battery voltage on any control circuit may keep the ECM powered up.