What does code P01B9 mean?

Q: What does code P01B9 mean?

Engine Oil Temperature Sensor B Circuit. P01B9 indicates that the powertrain control module has detected an abnormal condition in the electrical circuit for engine oil temperature sensor B, which is a second temperature sensor used on some engines to monitor oil temperature separately from the primary sensor. The computer compares the sensor signal against expected values and sets this code when the voltage or resistance falls outside the normal range, often due to a wiring fault or sensor failure.

DTC codes / P01xx · Fuel and air metering / P01B9

P01B9Engine Oil Temperature Sensor B Circuit

P01B9 indicates that the powertrain control module has detected an abnormal condition in the electrical circuit for engine oil temperature sensor B, which is a second temperature sensor used on some engines to monitor oil temperature separately from the primary sensor. The computer compares the sensor signal against expected values and sets this code when the voltage or resistance falls outside the normal range, often due to a wiring fault or sensor failure.

SystemPowertrain

Code typeGeneric (all makes)

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.