Engine Oil Pressure Sensor/Switch A Circuit High

What it means

The engine computer has detected that the oil pressure sensor signal voltage is above the normal range, giving an implausibly high pressure reading. This usually points to an open sensor ground, a short to a voltage source or a failed sensor.

Related codes: P0520P0521P0522P0524

Symptoms3

• Check engine light on.
• Oil pressure gauge reads very high or at the top of the scale.
• Oil pressure light does not work even if pressure drops, removing the warning.

Possible causes5

• Open sensor ground wire.
• Signal wire shorted to the supply wire or another voltage source.
• Internal sensor failure.
• Loose connector or corroded pins.
• Engine computer fault (rare).

How to diagnose5

1. Check the oil level to make sure the engine is protected while the warning is not working.
2. Watch the pressure reading on a scan tool with the key on, engine off, and then running.
3. Inspect the connector and wiring for damage or chafing.
4. Check continuity of the ground wire and confirm the signal wire is not shorted to a voltage source.
5. Substitute a known-good sensor or test it against the manufacturer specification.

How to fix5

1. Clean the connector and secure it properly.
2. Repair the open ground wire.
3. Repair the short between the signal wire and the voltage source.
4. Replace the oil pressure sensor.
5. Clear the codes and confirm the reading is plausible and the oil light works during the bulb check.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is usually low because the repair is a wire, connector or sensor; it rises if the sensor is hard to reach.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions