ECM Compressor Control Test

ECM Compressor Control Test:

NOTE: This test is to be performed with the Ignition Switch in RUN (engine not running) and the Mode Selector in NORM.

1. Measure the voltage to ground at the terminals of the ECM shown in the above chart. Leave the connectors in place.

^ If Battery voltage is not present at terminal D11, repair open in PPL wire (901).
^ If Battery voltage is not present at terminal B8, repair open in LT BLU wire (67).
^ If Battery voltage is not present at terminal A2, check for an open in the LT GRN/BLK wire (366). If wire is OK, replace the A/C Compressor Control Relay.

2. Using a fused jumper, temporarily connect terminal A2 to ground.

^ If the A/C Compressor Control Relay operates and engages compressor clutch, the A/C wiring is OK. If compressor does not operate, condition is due to ECM. Refer to Powertrain Management/Computers and Controls/Testing and Inspection/Procedures for ECM diagnosis. Testing and Inspection
^ If the A/C Compressor Control Relay does not operate or compressor does not turn on, replace the relay.