Powertrain, generic · Fuel and air metering

P01BD Engine Oil Temperature Sensor B Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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. P01BD covers brief or erratic signal faults of sensor B, the counterpart of P0199 – typically a loose contact or a harness chafing as the engine moves. 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.

Likely causes

Loose contact or corrosion at the sensor B connector
Harness chafing intermittently
Sensor B with internal hairline crack

Symptoms

  • Check engine light or only a stored code
  • Jumping oil temperature values
  • Usually no driving symptoms

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–250
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

engine oil temperature sensor bsensor wiring

Related codes

P01B9P01BAP01BBP01BCP0199

References: law.cornell.edu, saabwisonline.com.