With TCS

Checking A/C Activation, Steps 1, 2, 3:

1 Connect an ISAT scan tool, contact the SFI system and (with the engine running) enter command code EE64.

The status of the system is displayed on the ISAT:

^ A/C compressor switched off PAE64-ON. If not, go to point 2.

^ A/C compressor switched off PAE64-OFF. If not, go to point 5.

2 Check whether the A/C function is OK.


If it is not, connect a break-out box to the ECM and check whether battery positive voltage is present on pin 59 of the ECM when the A/C compressor is working.


If voltage is present, the ECM may be faulty. Review "Before Replacing ECM."

3 If not, check whether voltage is present on pin 86 of the A/C relay and that the voltage applied to pin 85 is about 1 V when the relay is in the operated condition (A/C compressor working).


(With the A/C compressor disconnected the voltage on pin 85 is about 12 V.)


If not, check the A/C function.

Checking A/C Activation, Steps 4, 5, 6:

4 If voltage is present, disconnect the ECM, switch off the ignition and check the lead to pin 59 of the ECM for continuity/shorting to ground. Take remedial action if the wiring is faulty.

5 Check whether the voltage applied to pin 85 of the A/C relay is about 12 V when the A/C function is not activated.


If it is not, check the relay and A/C function.

6 If no voltage is applied to the relay, use the break-out box (ECM disconnected) to check the lead to the ECM for shorting to battery positive voltage or to any component connected to the lead.


Take remedial action in the event of a faulty lead and/or connector, or any component through which voltage is applied to the lead.

If the lead is OK, the ECM may be faulty. Review "Before Replacing ECM."