ECM Compressor Control Test

ECM Connector Test:

1. Measure the voltage to ground at the following terminals of the ECM. Leave the connector in place.

^ If Battery voltage is not present at terminal 6, remove the connector from the Power Steering Idle Speed Pressure Switch.

- If Battery voltage is now present, replace the Power Steering Idle Speed Pressure Switch.
- If Battery voltage is still not present, check for a ground in the LT BLU/ORN (495) wire.

^ If Battery voltage is not present at terminal 21, check for an open in the DK GRN/WHT (459) wire.
^ If Battery voltage is not present at terminal 7, check for an open in the DK BLU (458) wire. If wire is good, replace the A/C Compressor Control Relay.

2. Temporarily connect terminal 7.

^ If A/C Compressor Control Relay operates and turns on compressor, the A/C Compressor Control wiring is good. 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 A/C Compressor Control Relay.