Diagnostic Instructions

DTC Descriptor

DTC P0532: Air Conditioning A/C Refrigerant Pressure Sensor Circuit Low Voltage

DTC P0533: Air Conditioning A/C Refrigerant Pressure Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit	Short to Ground	Open/High Resistance	Short to Voltage	Signal Performance
5-Volt Reference	P0530, P0532	P0530, P0532	P0530, P0533	--
A/C Refrigerant Pressure Sensor Signal Circuit	P0530, P0532	P0530, P0532	P0530, P0533	--
Low Reference Circuit	--	P0530, P0532	P0530, P0533	--

Circuit/System Description

The powertrain control module (PCM) monitors the high side refrigerant pressure via the A/C refrigerant pressure sensor. The PCM applies a 5-volt reference and a low reference to the sensor. Changes in the A/C refrigerant pressure cause the A/C refrigerant pressure sensor signal to the PCM to vary. 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. When the DTC is set, the PCM does not allow the A/C compressor clutch to engage. This is done to protect the compressor.

Conditions for Running the DTC

Conditions for Setting the DTC

P0532

The A/C refrigerant pressure sensor signal voltage is less than 0.2 volt for more than 3 seconds.

P0533

The A/C refrigerant pressure sensor signal voltage is more than 4.88 volts for more than 3 seconds.

Action Taken When the DTC Sets

Conditions for Clearing the DTC

Diagnostic Aids

A malfunction within the refrigerant system causing high pressure can cause this DTC to set.

Reference Information

Schematic Reference

HVAC Schematics

Connector End View Reference

HVAC Connector End Views

Description and Operation

Electrical Information Reference

Scan Tool Reference

Circuit/System Verification

Ignition ON, observe the scan tool A/C High Side Pressure parameter. The reading should be between 0.2 and 4.90 volts (9 and 453 psi), and change with pressure.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the A/C refrigerant pressure sensor.
2. Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit terminal 1 and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the PCM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 2 and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PCM.

4. Verify the scan tool A/C High Side Pressure Sensor parameter is less than 0.2 volts.

⇒	If greater than 0.2 volts, test the signal circuit for a short to voltage. If the circuit tests normal, replace the PCM.

5. Install a 3-amp fused jumper wire between the signal circuit terminal 3 and the 5-volt reference circuit terminal 2. Verify the scan tool A/C High Side Pressure Sensor parameter is greater than 4.90 volts.

⇒	If less than 4.90 volts, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PCM.

6. If all circuits test normal, replace the A/C refrigerant pressure sensor.

Component Testing

Static Test

1. Ignition OFF, disconnect the harness connector at the A/C refrigerant pressure sensor.
2. Test for 0.721k ohms of resistance between the 5-volt reference terminal 2 and the low reference terminal 1.

⇒	If the resistance is not equal to or close to the specified value, replace the A/C refrigerant pressure sensor.

3. Test for 0.721k ohms of resistance between the signal terminal 3 and the low reference terminal 3.

⇒	If the resistance is not equal to or close to the specified value, replace the A/C refrigerant pressure sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.