P0533

DTC P0533

CIRCUIT DESCRIPTION
The powertrain control module (PCM) monitors the high side refrigerant pressure through the A/C refrigerant pressure sensor. The PCM supplies 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.

DTC DESCRIPTOR
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.
- The battery voltage is between 11-18 volts.

CONDITIONS FOR SETTING THE DTC
- The PCM detects that the A/C pressure is less than 0 psi (0.01 volts).
- The PCM detects that the A/C pressure is more than 497 psi (4.94 volts).

ACTION TAKEN WHEN THE DTC SETS
- The PCM will not illuminate the malfunction indicator lamp (MIL).
- The PCM stores the Failure Records.
- The A/C compressor clutch is disabled.

CONDITIONS FOR CLEARING THE DTC
- The history DTC will clear after 40 consecutive ignition cycles have occurred without a malfunction.
- The DTC can be cleared by using the scan tool.
- The DTC will become history if the PCM no longer detects a failure.

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 high pressure.
- Visually inspect the A/C components and lines for damage.
- Refer to Testing for Intermittent Conditions and Poor Connections. Component Tests and General Diagnostics

TEST DESCRIPTION

Step 1 - Step 9:

Step 10 - Step 17:

The numbers below refer to the step numbers on the diagnostic table.
4. Tests for the proper operation of the circuit in the low voltage range.
5. 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.
6. Tests for a short to voltage in the 5-volt reference circuit.
7. Tests for a high resistance or an open in the low reference circuit.