A/C Inoperative and/or Actual Engine Idle Speed Does Not Match Commanded Idle Speed After PCM Replacement or Reprogramming. Saturn Saturn 1992

For 1990-2009 cars

# A/C Inoperative and/or Actual Engine Idle Speed Does Not Match Commanded Idle Speed After PCM Replacement or Reprogramming

Subject: | A/C Inoperative and/or Actual Engine Idle Speed Does Not Match Commanded Idle Speed After PCM Replacement or Reprogramming (Reprogram PCM with Saturn Service Stall Software Version 1.01 or Higher)

Models: | 1992 Saturn vehicles

### Condition

Customer may list concern as A/C inoperative or an erratic engine idle condition after PCM reprogramming.

### Cause

PCM calibration may lead to erratic engine idle speed and prohibit A/C clutch command.

### Correction

Check for proper PCM calibration by verifying A/C compressor clutch operation and reprogram PCM if needed.

### Procedures

1. Verify that the ambient air temperature is above 18 degrees C (65°F) by viewing the intake air temperature (IAT) on Scan tool.
2. With the engine at idle, set the HVAC fan switch to LOW and press the A/C button so that the A/C switch indicator light is On.
3. Check to see if the compressor clutch is engaged.

• | If compressor clutch is not engaged, use a Scan tool to check the status of the A/C REQUEST and A/C CLUTCH. (These data parameters can be found on the Tech 2 under the "Engine Data" display table.) Under these conditions, A/C REQUEST should read YES and A/C CLUTCH should read ON.

• | -- If the A/C REQUEST reads YES, but the A/C CLUTCH reads OFF, reprogram the PCM using the Service Stall System software version 1.01 or higher.

• | If the compressor clutch is engaged or A/C REQUEST or A/C CLUTCH status does not read as stated above, continue to step 4.

4. Verify proper A/C system operation. If the above conditions continue or if the A/C system continues to be inoperative, refer to one of the following:

• | The 1991 - 1993 HVAC Service Manual for further A/C clutch diagnosis.

• | The symptom tables in front of the 1991 - 1994 Electronic Engine Controls Service Manual for further engine idle speed diagnosis.

### Claim Information:

To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System using labor operation code J6355 (EEPROM reprogramming), or if another procedure is performed, refer to the appropriate Electronic Labor Time Guide for the correct Labor Operation Code and Time.