Without TCS

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

1 Connect an ISAT scan tool, contact the SFI system and enter command code EE64.

The status of the system is displayed on the ISAT:


^ A/C compressor switched on@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. Turn the ignition switch to the Drive position and, with the A/C function activated, check whether voltage is present on pin 59 of the ECM.

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

3 If no voltage is present, check whether voltage passes through the antifreeze thermostat when the A/C compressor is working. If it does not, check the A/C function.

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

4 If voltage is present, disconnect the ECM, switch the ignition off and use the break-out box to check the lead to pin 59 of the ECM for continuity/shorting to ground.

Take remedial action if the lead and/or connectors are faulty.

5 Check that no voltage is applied to the antifreeze thermostat when the A/C function is not activated.

If it is, check the A/C function.

6 If no voltage is applied to the antifreeze thermostat, 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."