Engine Oil Pressure Sensor/Switch "A" Range/Performance

What it means

The engine oil pressure sensor is sending a signal that is electrically valid but does not make sense compared with other sensors. The engine oil pressure sensor reports engine oil pressure to the ECU and the oil warning light or gauge. This usually points to a sensor that is reading wrong, or to a real mechanical problem it is reporting correctly, rather than a broken wire.

Symptoms

• Check engine light on
• Oil pressure light flickering or staying on
• Oil pressure gauge reading zero or maximum

Probable causes

Most likely first

1. 1Real low oil pressure: low oil level, wrong oil viscosity, worn oil pump or bearings
2. 2Oil leaking into the sensor connector
3. 3Failing sensor giving an inaccurate reading
4. 4Poor connection at the sensor connector

How to diagnose it

Work through these in order before buying parts

1. 1Record the code and its freeze frame data (speed, load, temperature when it set), then clear it and see if it comes back.
2. 2Inspect the engine oil pressure sensor connector and wiring (screwed into the engine block or oil filter housing). Look for corrosion, bent or pushed-back pins, oil contamination and chafed insulation.
3. 3Watch the engine oil pressure sensor reading on live data. Compare the reading with a mechanical oil pressure gauge fitted in place of the sensor.
4. 4Compare the engine oil pressure sensor reading against related sensors and the real-world condition. If they disagree, find out which one is telling the truth before buying parts.
5. 5If the wiring checks out, test the sensor itself against the specification in a service manual.
6. 6Check for technical service bulletins (TSBs) or software updates for your make and model; some codes have known factory fixes.

Common fixes

• Fix the underlying problem the sensor is reporting, if real
• Replace the engine oil pressure sensor if it reads wrong against a known-good reference