Checking the A/C Relay

Checking A/C Relay, Steps 1 & 2:

1 Connect an ISAT scan tool, contact the SFI system and enter command code 3042 (except TCS).


On cars with TCS, contact the ETS system (system No. 3 in the ISAT) and enter command code 550.


Check whether the relay works (at 1 Hz for 10 seconds) by listening to the sound it makes.


2 If it does not work, turn the ignition switch to the Drive position and check whether voltage is present on terminal 86 of the relay. If it is not, remove the relay and check whether the resistance across pins 85 and 86 is about 60 ohms.


If it is not, replace the A/C relay.


NOTE:
When command code 30XX has been used, the car cannot be started for the following 12 minutes. Use command code FF00 to clear the function, following which the car can be started.

Checking A/C Relay, Step 3:

3 With the ignition switched off, connect a break-out box to the ECM wiring harness (ECM disconnected). Also unplug the ETS control module's connector.


Check the lead between pin 59 of the ECM and pin 85 of the A/C relay for continuity/shorting to ground.


Remedy any faulty leads/connectors.

4 If malfunctioning of the A/C relay persists in spite of the above checks, the ECM may be faulty. Review "Before Replacing ECM."