GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Holden 🢒 2005 🢒 Calais 🢒 DTC 🢒 DTC P1539

DTC Description

This diagnostic procedure covers DTC P1539, A/C Clutch Status Circuit High Voltage.

Circuit Description

The powertrain control module (PCM) activates the A/C clutch relay when the PCM detects that A/C has been requested. When activated, voltage should be present at both the A/C compressor clutch and the A/C clutch status circuit at the PCM.

DTC P1539 sets if the PCM detects voltage on the A/C clutch status terminal when the system has not requested the A/C.

Conditions for Running the DTC

The A/C clutch is not requested.

Conditions for Setting the DTC

Voltage is detected on the A/C status circuit for more than 15 seconds after the PCM has disengaged the A/C clutch relay.

Conditions for Clearing the DTC

The A/C clutch feedback circuit DTC is a Type C DTC. Refer to Engine Controls System Component Description for action taken when a Type C DTC sets and Conditions for Clearing a Type C DTC.

Additional Information
    • Refer to Powertrain Control Module Description for details of the PCM operation.
    • For an intermittent fault condition, Intermittent Conditions
    • The A/C refrigerant pressure sensor circuit diagnostic table is developed with the assumption that the A/C refrigerant system is functioning correctly. Therefore, rectify any A/C refrigerant system fault conditions before proceeding with this diagnostic procedure.
    • Since fault condition in a wiring connector may trigger DTCs, always test the connectors related to this diagnostic procedure for shorted terminals or poor wiring connection before replacing any component. Refer to Testing for Intermittent Conditions and Poor Connections for information on electrical fault diagnosis.
    • Refer to HVAC Schematics and HVAC Connector End Views to aid in the diagnosis procedures.

Step

Action

Yes

No

1

Was the Main Diagnostic Table performed?

Go to Step 2

Refer to Diagnostic System Check - HVAC Systems - Automatic

2

Using Tech 2 select Engine/Diagnostic Trouble Codes/Read DTC Information.

Does DTC P0645 fail this ignition cycle?

Refer to DTC P0645

Go to Step 3

3

Test the A/C refrigerant system. Refer to Air Conditioning (A/C) System Performance Test.

Was any fault found and rectified?

Go to Step 12

Go to Step 4

4
  1. Observe the Freeze Frame/Failure Record for this DTC.
  2. Switch off the ignition for 30 seconds.
  3. Operate the vehicle within the conditions for running the DTC or within the conditions in the Freeze Frame/Failure Records.
  4. Using Tech 2 select Engine/Diagnostic Trouble Codes/Read DTC Information.

Does DTC P1539 fail this ignition cycle?

Go to Step 5

Refer to Diagnostic Aids for the A/C Clutch Feedback Circuit DTC

5
  1. Turn ON the ignition, with the engine not running.
  2. Ensure the A/C is switched OFF.
  3. Using a digital multimeter, measure the voltage between the A/C clutch feedback circuit and the PCM housing.

Is any voltage detected?

Go to Step 5

Go to Step 6

6
  1. Switch OFF the ignition.
  2. Remove the A/C relay.
  3. Turn ON the ignition, with the engine not running.
  4. Using a digital multimeter, measure the voltage between the A/C clutch feedback circuit and the PCM housing.

Is any voltage detected?

Go to Step 9

Go to Step 6

7
  1. Start the engine.
  2. Using Tech 2 select Engine/Data Display/Engine Data 1 and scroll down to A/C Request (Air Conditioning).

Does Tech 2 indicate that the A/C turns ON and OFF when the A/C switch is toggled?

Go to Step 8

Refer to Diagnostic Starting Point - Computer/Integrating Systems

8
  1. Turn on the ignition, with the engine not running.
  2. Using Tech 2 select Engine/Data Display/Engine Data 1 and scroll down to A/C Request (Air Conditioning).
  3. Ensure the A/C is switched OFF.
  4. Using a digital multimeter, test for continuity between the control circuit of the A/C clutch relay and a known ground.

Does the multimeter indicate continuity when Tech indicates the A/C is OFF?

Go to Step 9

Go to Step 10

9

Test the control circuit of the A/C clutch relay for a short to ground fault condition. Refer to Testing for Intermittent Conditions and Poor Connections for information on electrical fault diagnosis.

Was any fault found and rectified?

Go to Step 12

Go to Step 11

10

Repair the short to voltage fault condition in the A/C clutch circuit or A/C clutch feedback circuit. Refer to Wiring Repairs for information on electrical fault diagnosis.

Was the repair completed?

Go to Step 12

--

11

Replace the A/C Relay R11. Refer to Electrical Center Identification Views.

Was the repair completed?

Go to Step 12

--

12

Replace the PCM. Refer to Powertrain Control Module Replacement.

Was the repair completed?

Go to Step 12

--

13
  1. Using Tech 2, clear the DTCs.
  2. Switch OFF the ignition for 30 seconds.
  3. Start the engine.
  4. Operate the vehicle within the Conditions for Running the DTC.

Does DTC P1539 fail this ignition cycle?

Go to Step 2

Go to Step 13

14

Using Tech 2, select the DTC display function.

Are there any DTCs displayed?

Go to the appropriate DTC table

System OK

When all the diagnosis and repairs are completed, check the engine management system for correct operation.