P01BAEngine Oil Temperature Sensor B Range/Performance
- 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
- The engine oil temperature sensor B is an NTC thermistor fed with 5 V through a resistor: the hotter the oil, the lower the signal voltage. The engine module uses the oil temperature for variable cam timing (Ford disables it with cold oil or a sensor fault), engine protection and the oil life monitor; many engines have no such sensor and use a calculated oil temperature instead. Sensor B is a second oil temperature sensor whose position is defined by the manufacturer. P01BA is the plausibility fault of sensor B, the counterpart of P0196 – presumably a cold-start comparison, a warm-up check or a comparison with sensor A or a model, as GM documents for sensor A. No manufacturer document using the B-sensor codes was found, so it is unclear who fits a sensor B; the description follows sensor A and CARB's circuit monitoring requirement.
- What you may notice
- Check engine light on (depending on manufacturer)
- Implausible oil temperature values in scan data
- Usually no driving symptoms
- Likely causes
- LikelySensor B drifting or stuck
- PossibleComparison sensor (oil sensor A, coolant) faulty
- PossibleContact resistance in the connector
- RareThermal management or oil cooler fault (genuine deviation)
- 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: €50 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.