DTC P0532 or P0533. GMC Truck Canyon Pickup

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 2006 🢒 Canyon Pickup - 4WD 🢒 Brakes 🢒 Park Brake 🢒 DTC P0532 or P0533

Circuit Description

The powertrain control module (PCM) monitors the high side refrigerant pressure through an 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 commands the cooling fans ON. When pressure is too high or too low, the PCM will not allow the A/C compressor clutch to engage. The PCM sends the A/C pressure data to the dash integration module (DIM) over the Class 2 serial data circuit. The DIM will command the inline A/C orifice solenoid to increase or decrease the high side pressure. This keeps the high side pressure in a normal operating range. This will prevent the A/C compressor clutch from disengaging under normal operating conditions. The DIM will not request A/C compressor clutch engagement if the A/C pressure is too high.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

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

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

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

•	A/C pressure of less than 0.1 volt or more than 4.92 volts

•	The condition must be present for more than 5 seconds.

Action Taken When the DTC Sets

•	The PCM will not illuminate the malfunction indicator lamp (MIL).

•	The PCM will store the conditions present when the DTC set as Fail Records data only.

Conditions for Clearing the DTC

•	The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.

•	The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

Test the following conditions:

•	Visually inspect the sensor for contamination or damage.

•	Inspect for the following that may affect the sensors accuracy:

-	A malfunction within the refrigerant system causing low pressure

-	Visually inspect the A/C components and lines for damage.

•	Refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

The number below refers to the step number on the diagnostic table.

This step tests the ability of the A/C refrigerant pressure sensor to create a voltage signal for the PCM to monitor the A/C refrigerant pressure. Measure the voltage at the A/C refrigerant pressure sensor, if the voltage is measured at the connector for the sensor, misdiagnosis will occur.

Step

Action

Value(s)

Yes

Schematic Reference: HVAC Schematics

Connector End View Reference: HVAC Connector End Views

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

Does the scan tool indicate that DTC P0532 or P0533 is current?

Go to Step 3

Go to Diagnostic Aids

Turn OFF the ignition.
Disconnect the A/C refrigerant pressure sensor.
Turn ON the ignition, with the engine OFF.
Measure the voltage from the 5-volt reference circuit to the low reference circuit of the A/C refrigerant pressure sensor.

Does the voltage measure near the specified value?

5 V

Go to Step 5

Go to Step 4

Measure the voltage from the 5-volt reference circuit of the A/C refrigerant pressure sensor to a good ground.

Does the voltage measure near the specified value?

5 V

Go to Step 7

Go to Step 6

With the A/C refrigerant pressure sensor disconnected, connect a jumper wire between the A/C refrigerant pressure sensor and the electrical connector of the A/C refrigerant pressure sensor for the following circuits:

•	The 5-volt reference circuit

•	The low reference circuit

Measure the voltage at the A/C refrigerant pressure sensor terminal for the A/C refrigerant pressure sensor signal.

Does the voltage measure less than the specified value?

1.5 V

Go to Step 8

Go to Step 9

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