P0532

What it means

P0532 means the control unit has seen the signal voltage from the air conditioning refrigerant pressure sensor (sensor A) fall below the expected range. This usually points to a short to earth, an open circuit or a failed sensor, or to very low refrigerant pressure in the system. The control unit may stop the A/C compressor from engaging to protect it.

Symptoms

• A/C blows warm or does not cool
• A/C compressor does not engage or clutch does not click in
• Air conditioning warning light or A/C button indicator flashing on some models
• Cooling fans running constantly or at odd times
• Slightly raised idle or poor idle quality when A/C is requested
• Check engine light on

Possible causes

• Low refrigerant charge from a leak, so pressure is genuinely below the sensor's working rangelikely
• Faulty A/C refrigerant pressure sensor reading low or out of rangelikely
• Damaged, chafed or corroded wiring, or a signal wire shorted to earthpossible
• Poor connection or corroded terminals at the sensor plugpossible
• Open circuit or short on the sensor 5 volt reference supply or earth feedpossible
• Fault inside the engine control unit or A/C control modulerare

How to diagnose

1. Read and note the freeze frame data and any other stored codes, especially other sensor reference voltage faults
2. Check whether the A/C blows cold and whether the compressor clutch engages, to judge if the refrigerant charge is low
3. Visually inspect the sensor, its plug and the wiring for damage, chafing, corrosion or water ingress
4. Check the A/C system pressures with suitable gauges to confirm whether actual pressure is low or normal
5. With the ignition on, view the live A/C pressure reading and compare it with the gauge pressure; a reading stuck low with normal pressure points to the sensor or wiring
6. Unplug the sensor and check for a 5 volt reference, a good earth and no short to earth on the signal wire, using the wiring diagram for the model
7. Check the wiring for continuity and for shorts between the sensor and control unit
8. If everything checks out, test or substitute the sensor and consider the control unit only as a last step

How to fix

• Find and repair the refrigerant leak, then evacuate and recharge the system to the correct specification
• Replace the faulty A/C pressure sensor, following the model's procedure to avoid losing refrigerant if it is not fitted with a service valve
• Repair or replace damaged wiring and clean or renew corroded connector terminals
• Restore the reference supply or earth circuit fault found during testing
• Repair or replace the control unit only after all other causes are ruled out, and have it programmed if required

Can I keep driving?

Nearby codes

• P0531GenericA/C Refrigerant Pressure Sensor A Circuit Range/Performance
• P0533GenericA/C Refrigerant Pressure Sensor A Circuit High