GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2006 🢒 Rendezvous - FWD 🢒 Accessories 🢒 Navigation Systems 🢒 DTC P0532 or P0533

Circuit Description

The powertrain control module (PCM) or engine control module (ECM) monitors the high side refrigerant pressure via a A/C refrigerant pressure sensor. When the pressure is high the signal voltage is high. When the pressure is low the signal voltage is low. When pressure is high the PCM/ECM commands the cooling fans on. When pressure is too high or too low the PCM/ECM will not allow the A/C compressor clutch to engage.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • P0532 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit Low Voltage
    • P0533 Air Conditioning (A/C) Refrigerant Pressure Sensor Circuit High Voltage

Conditions for Running the DTC
    • The engine is running.
    • A/C has been requested.

Conditions for Setting the DTC
    • The PCM/ECM detects the signal circuit is less than 5 counts (0.09 volt) or more than 250 counts (4.90 volts).
    • The condition exists for 20 seconds.

Action Taken When the DTC Sets
    • The PCM/ECM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM/ECM stores the failure records.
    • The A/C compressor clutch is disabled.

Conditions for Clearing the DTC
    • The DTC will become history if the PCM/ECM no longer detects a failure.
    • The history DTC will clear after 40 fault-free ignition cycles.
    • The DTC can be cleared with a scan tool.

Diagnostic Aids

If the condition is not present refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. If the pressure signal voltage stays high after disconnecting the pressure sensor electrical connector, the signal circuit is shorted to voltage, or the PCM/ECM is faulty.

    2.

  2. Tests for a high resistance or for an open in the ground circuit.

    3.

  3. This vehicle is equipped with a PCM/ECM which utilizes an electrically erasable programmable read only memory (EEPROM). Before you replace the PCM/ECM, program the new PCM/ECM.

Step

Action

Values

Yes

No

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Important: The ambient air temperature must be above 3°C (38°F).

  1. Turn OFF the ignition.
  2. Inspect the A/C compressor for free rotation operation.
  3. Start the engine.
  4. Place the HVAC control module in the OFF position.

Does the A/C compressor operate?

--

Go to HVAC Compressor Clutch Does Not Disengage

Go to Step 3

3
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the A/C High Side Pressure parameter in the PCM/ECM Engine Data list.

Does the scan tool indicate that the A/C High Side Pressure parameter is within the specified range?

0.1-4.9 V

Go to Diagnostic Aids

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the A/C refrigerant pressure sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the A/C High Side Pressure parameter.

Does the scan tool indicate that the A/C High Side Pressure parameter is less than the specified value?

0.1 V

Go to Step 5

Go to Step 11

5
  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the 5-volt reference circuit and the signal circuit of the A/C refrigerant pressure sensor.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, observe the A/C High Side Pressure parameter.

Does the scan tool indicate that the A/C High Side Pressure parameter is greater than the specified value?

4.9 V

Go to Step 6

Go to Step 9

6
  1. Disconnect the fused jumper wire.
  2. Measure the voltage between the 5-volt reference circuit of the A/C refrigerant pressure sensor and the ground circuit of the A/C refrigerant pressure sensor.

Is the voltage measurement less than the specified value?

5.0 V

Go to Step 7

Go to Step 8

7

  1. Turn OFF the ignition.
  2. Measure the resistance from the low reference circuit of the A/C refrigerant pressure sensor to a good ground.

Is the resistance measurement near the specified value?

5 ohms

Go to Step 13

Go to Step 12

8

Test the 5-volt reference circuit of the A/C refrigerant pressure sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

9

Test the 5-volt reference circuit of the A/C refrigerant pressure sensor for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 10

10

Test the signal circuit of the A/C refrigerant pressure sensor for a short to ground, for a high resistance, or for an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

11

Test the signal circuit of the A/C refrigerant pressure sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

12
  1. Disconnect the powertrain control module (PCM)/engine control module (ECM).
  2. Test the low reference circuit of the A/C refrigerant pressure sensor for high resistance or for an open. Refer to Testing for Intermittent Conditions and Poor Connections and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

13

Inspect for bad connections at the harness connector of the A/C refrigerant pressure sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 15

14

Inspect for bad connections at the harness connector of the PCM/ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

15

Replace the A/C refrigerant pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement .

Did you complete the replacement?

--

Go to Step 17

--

16

Replace the PCM/ECM. Refer to Control Module References .

Did you complete the replacement?

--

Go to Step 17

--

17
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running, as specified in the supporting text.

Does the DTC set again?

--

Go to Step 2

System OK