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.

Did you perform the HVAC Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - HVAC Systems - Automatic

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, perform the Recalibrate all Motors command in Instrument Panel Module Special Functions.

Does the scan tool display any DTCs?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

1. Start the engine.
2. Place the blower motor switch in the OFF position.
3. Place the A/C switch in the OFF position.

Does the A/C compressor operate?

Go to Step 4

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

With the scan tool, observe the A/C Relay Command parameter in the powertrain control module (PCM) Engine Data List.

Does the scan tool indicate the A/C Relay Commanded parameter is ON?

Go to Step 5

Go to Step 8

With the scan tool, observe the Control Head, desired, parameter in the dash integration module (DIM) A/C Information List.

Does the scan tool display OFF?

Go to Step 6

Go to Step 13

With the scan tool, observe the A/C Requested parameter in the instrument panel module (IPM) HVAC System Data list.

Does the scan tool display yes?

Go to Step 7

Go to Step 14

With a scan tool, observe the A/C Clutch, desired, parameter in the DIM A/C Information List.

Does the scan tool display OFF?

Go to Step 16

Go to Step 15

1. Turn OFF the ignition.
2. Disconnect the A/C compressor clutch relay.
3. Turn the ignition ON.

Does the A/C compressor clutch disengage?

Go to Step 12

Go to Step 10

Test the A/C compressor clutch relay control circuit of the A/C compressor clutch relay for a short to ground. A short to ground on the A/C compressor clutch control circuit will set DTC P1546. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 12

Test the A/C compressor clutch supply voltage circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 11

Inspect for poor connections at the harness connector of the A/C compressor clutch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 18

Inspect for poor connections at the A/C compressor clutch relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 17

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 in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 19

Inspect for poor connections at the harness connector of the IPM Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 20

Inspect for poor connections at the DIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 21

Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 23

Go to Step 22

Replace the A/C compressor clutch relay. Refer to Compressor Relay Replacement in Heating, Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 23

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Replace the A/C compressor clutch. Refer to Compressor Clutch Plate and Hub Assembly Removal and Compressor Clutch Plate/Hub Assembly Install in Heating, Ventilation and Air Conditioning.

Did you complete the replacement?

Go to Step 23

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Replace the HVAC control module. Refer to HVAC Control Module Replacement .

Did you complete the replacement?

Go to Step 23

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Replace the IPM. Refer to Instrument Panel Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 23

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Replace the DIM. Refer to Dash Integration Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 23

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Important:  Perform the programming procedure for the PCM.

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 3.8L.

Did you complete the replacement?

Go to Step 23

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3