P0533

DTC P0533

CIRCUIT DESCRIPTION
The engine control module (ECM) monitors the high side refrigerant pressure through an air conditioning (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 the pressure is high, the ECM commands the cooling fans ON. When the pressure is too high or too low, the ECM will not allow the A/C compressor clutch to engage.

DTC DESCRIPTORS
This diagnostic procedure supports the following DTCs:
- DTC P0531 A/C Refrigerant Pressure Sensor Performance
- DTC P0532 A/C Refrigerant Pressure Sensor Circuit Low Voltage
- DTC P0533 A/C Refrigerant Pressure Sensor Circuit High Voltage

CONDITIONS FOR RUNNING THE DTC
- The engine is running.
- A/C OFF when P0531 is set.

CONDITIONS FOR SETTING THE DTC

P0531
The ECM detects the A/C pressure signal circuit is more than 4.5 volts for 4 minutes.

P0532
The ECM detects an A/C pressure of less than 0.1 volt for 1.6 seconds.

P0533
The ECM detects an A/C pressure of more than 4.9 volts for 1.6 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The ECM will not illuminate the malfunction indicator lamp (MIL).
- The ECM stores the failure records.
- The A/C compressor clutch is disabled.
- SERVICE A/C SYSTEM displays on the driver information center (DIC).
- A/C OFF displays on the HVAC control module.
- The A/C compressor clutch will not be disabled if only DTC P0531 is set.

CONDITIONS FOR CLEARING THE DTC
- The ECM will not store failure records if only DTC P0531 is set.
- The DTC will become history if the ECM no longer detects a failure.
- The history DTC will clear after 40 fault-free ignition cycles.
- Clear the DTC with a scan tool then cycle the ignition.

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

TEST DESCRIPTION

Steps 1-9:

Steps 10-16:

The numbers below refer to the step numbers on the diagnostic table.
3. Tests for the proper operation of the circuit in the low voltage range.
4. Tests for the proper operation of the circuit in the high voltage range. If the fuse in the jumper opens when you perform this test, the signal circuit is shorted to ground.
5. Tests for a short to voltage in the 5-volt reference circuit.