Test F - ECM Compressor Control Test

ECM Compressor Control Test:

1. Reconnect the A/C Compressor Control Relay. Remove the connector from the ECM and measure the voltage to ground at the following terminals.
^ If all voltages are correct, proceed to step 2.
^ If the voltage at terminal 19 is incorrect, check for an open in the BRN (449) wire. If wire is OK, replace the A/C Compressor Control Relay.
^ If voltage is incorrect at terminal J, repair open in the LT GRN (66) wire.
2. Connect terminal 19 to ground using a fused jumper.
^ If the A/C Compressor Control Relay operates and turns on compressor, the Compressor Control wiring is good. Refer Computers and Control Systems for ECM diagnostics.
^ If the A/C Compressor Control Relay does not operate or the compresor does not turn on, replace the A/C Compressor Control Relay.