What it means
The control module monitors the voltage signal from engine oil pressure sensor or switch B. It sets this code when the signal rises above the calibrated range; the code alone does not confirm that actual oil pressure is high.
At a glance
- Usually lights the check-engine light
How it works
Engine oil pressure sensor or switch B sends a voltage signal to the control module for oil-pressure monitoring. P055D sets when that signal rises above the calibrated range; a short to voltage or sensor fault can cause it, and the code alone does not establish that actual oil pressure is high.
Common causes
Most likely first.
- Signal wire shorted to voltage
- Oil pressure sensor or switch B failed
- Open or high-resistance wiring or connector
- Actual oil pressure outside the expected range
Symptoms
- Check-engine light may come on
- Oil pressure warning light may come on
- Oil pressure gauge or display may read high or erratically
- Engine noise if actual oil pressure is abnormal
How to diagnose it
- Check for an oil-pressure warning, abnormal gauge reading, or engine noise, and note whether the reading changes with engine operation.
- Record freeze-frame data and compare sensor B live data with any other available oil-pressure information.
- Inspect the B sensor connector and wiring for corrosion, loose pins, damage, or contact with a voltage source.
- Test the signal circuit for shorts to voltage, opens, and high resistance against the manufacturer's specification.
- If the circuit passes, test sensor or switch B and verify actual oil pressure using the manufacturer's specified method.
Common fixes
- Clean and secure a loose or corroded sensor B connector.
- Repair wiring shorted to a voltage source or otherwise damaged.
- Replace sensor or switch B if it fails testing.
- Repair any confirmed mechanical oil-pressure problem.
Can I keep driving?
If an oil-pressure warning appears, the gauge is abnormal, or the engine makes unusual noise, stop and have the cause checked before continuing. The high signal may be electrical, but abnormal actual pressure can also harm the engine.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.