HVAC Compressor Clutch Does Not Disengage
WARNING: This page is about a different car, the 2007 Pontiac G5 Pursuit, 2007 Pontiac G5, and 2007 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.
HVAC Compressor Clutch Does Not Disengage
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| Schematic Reference: HVAC Schematics Connector End View Reference: HVAC Connector End Views DEFINITION: The A/C compressor clutch will not disengage when an A/C request has not been made and a powertrain DTC has not been set. |
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| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Go to DIAGNOSTIC SYSTEM CHECK - VEHICLE |
| 2 |
|
- | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections |
| 3 | With a scan tool, observe the A/C request signal parameter in the engine control module (ECM) or powertrain control module (PCM), General Info Inputs/Outputs data list. Does the scan tool indicate that the A/C request signal parameter is YES? |
- | Go to Step 4 | Go to Step 6 |
| 4 | Test the A/C request signal circuit for a short to voltage. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 5 |
| 5 |
|
- | Go to Step 14 | Go to Step 13 |
| 6 | With a scan tool, command the A/C compressor clutch relay ON and OFF. Does the A/C compressor clutch relay turn ON and OFF with each command? |
- | Go to Step 7 | Go to Step 9 |
| 7 | Remove the A/C compressor clutch relay. Is the A/C compressor ON? |
- | Go to Step 10 | Go to Step 8 |
| 8 | Measure the resistance between the switch side A/C compressor clutch relay terminals. Does the resistance measurement equal the specified value? |
∞ | Go to Step 9 | Go to Step 12 |
| 9 | Test the A/C clutch relay control circuit for a short to ground. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 14 |
| 10 | Test the A/C clutch relay control circuit for a short to voltage. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 12 |
| 11 | Test the A/C compressor clutch supply voltage circuit for a short to voltage. Refer to Circuit Testing
and Wiring Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 16 |
| 12 | Inspect for poor connections at the A/C compressor clutch relay. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 15 |
| 13 | Inspect for poor connections at the harness connector of the HVAC control module. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 17 |
| 14 | Inspect for poor connections at the harness connector of the ECM or PCM. Refer to Testing for Intermittent Conditions and Poor Connections
and Connector Repairs
. Did you find and correct the condition? |
- | Go to Step 19 | Go to Step 18 |
| 15 | Replace the A/C compressor clutch relay. Did you complete the replacement? |
- | Go to Step 19 | - |
| 16 | Replace the A/C compressor clutch. Refer to Compressor Replacement (RPO LSJ)
or Compressor Replacement (RPOs L61, LE5)
. Did you complete the replacement? |
- | Go to Step 19 | - |
| 17 | Replace the HVAC control module. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
- | Go to Step 19 | - |
| 18 | Replace the ECM or PCM. Refer to Control Module References
for replacement, setup, and programming. Did you complete the replacement? |
- | Go to Step 19 | - |
| 19 | Operate the system in order to verify the repair. Did you correct the condition? |
- | System OK | Go to Step 3 |