P1462

What it means

P1462 on a Lincoln means the powertrain control module has seen the signal voltage from the air conditioning pressure sensor sitting higher than the expected range. The PCM uses this sensor to protect the A/C system and to manage compressor and cooling fan operation. A high voltage usually points to an open circuit, a short to a voltage supply, or a faulty sensor, but it can also reflect a genuinely high refrigerant pressure.

Symptoms

• A/C blows warm or does not cool properly
• A/C compressor will not engage or cuts out
• Cooling fans running constantly or at the wrong time
• Engine idle slightly unstable or higher than normal when A/C is requested
• Check engine light on

Possible causes

• Faulty A/C pressure sensor giving a high or out-of-range signallikely
• Damaged, corroded or loose connector at the pressure sensorlikely
• Open circuit in the signal or ground wire, or signal wire shorted to the reference voltage or a power supplypossible
• Genuinely excessive refrigerant pressure from overcharge, blocked condenser, poor airflow or a failed cooling fanpossible
• Restriction in the A/C system, such as a blocked expansion device or receiver/drierrare
• Fault within the PCM affecting the sensor circuitrare

How to diagnose

1. Read all stored and pending codes and note the freeze frame data, including engine temperature and A/C request status.
2. Visually inspect the pressure sensor connector and wiring for damage, corrosion, water ingress, chafing or poor pin tension.
3. Check the condenser for blockage by debris and confirm the cooling fans operate correctly.
4. With a scan tool, view the A/C pressure sensor live data with the engine off and with the A/C running, and compare with the reading from a set of manifold gauges.
5. If the live data does not match the gauge pressure, check the sensor reference voltage, signal and ground at the connector against the manufacturer's wiring diagram for your model.
6. Test the signal wire for continuity and for shorts to voltage or ground, with the connector disconnected from the PCM where the procedure requires it.
7. Check the refrigerant charge and system for restrictions, using recovery and weighing methods by a qualified A/C technician.
8. Only after circuits and the sensor are proven good, consider the PCM, following the manufacturer's diagnostic procedure.

How to fix

• Replace the A/C pressure sensor if its output is wrong compared with actual system pressure.
• Repair or replace the damaged connector terminals or wiring, including any short or open circuit.
• Clean or replace a blocked condenser and repair any faulty cooling fan or fan circuit.
• Recover and recharge the A/C system to the correct charge weight if it is overcharged, contaminated or low.
• Replace any restricted component found in the refrigerant circuit and then recharge the system correctly.
• Replace or reprogram the PCM only if it is confirmed faulty, as per the manufacturer's procedure.

Can I keep driving?

This code for other makes

• P1462BMWHeated Catalyst Internal Control Module Checksum ROM Error
• P1462FordAir Conditioning Pressure Sensor Circuit High Input
• P1462MercuryAir Conditioning Pressure Sensor Circuit High Input
• P1462OtherA/C pressure sensor circuit voltage high
• P1462VolkswagenExhaust Gas Temperature Control Bank 2 Range Performance

Nearby codes

• P1461LincolnAir Conditioning Pressure Sensor Circuit Low Input
• P1463LincolnAir Conditioning Pressure Sensor Insufficient Pressure Change