P055AEngine Oil Pressure Sensor/Switch B Circuit
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Oil pressure sensor B is a second sensor, usually in the oil feed to the cam phasers or valve lift switching – on GM's 2.5 L (2014 Impala and Malibu) in the camshaft cover – while sensor A measures the main gallery. Documented only by GM (type B, two trips); Ford uses no sensor B. P055A is the general circuit fault without low/high assignment. No manufacturer document available to us uses it – GM reports sensor B only as P055B–P055D. The module then uses a substitute value and may set cam phasers or valve lift to their base position.
- What you may notice
- Check engine light on
- Cam phasing or valve lift switching possibly restricted
- Often no noticeable symptoms
- Likely causes
- LikelyConnector or harness to sensor B open, corroded or oily
- PossibleSensor B open internally
- PossibleShared 5 V reference or ground disturbed
- RareEngine module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.