Test E: ECM Compressor Control Test

1. Remove the connectors from the ECM and use test lamp to ground at the following terminals of the connector.

Test E ECM Compressor Control Test:

^ If both tests are good, proceed to step 2.
^ If test lamp does not light at terminal D11, check for an open in PPL wire (901).
^ If test lamp does not light at terminal B8, check for an open in the LT BLU wire (67).

2. Temporarily connect terminal A2 to ground using a fused jumper.

^ If A/C Compressor Control Relay operates and turns on compressor, the A/C Compressor Control circuit wiring is good, refer to ECM Diagnostics.
^ If A/C Compressor Control Relay does not operate or compressor does not turn on, check the LT GRN/BLK wire for an open. If wire is good, replace the A/C Compressor Control Relay.