P01BC Engine Oil Temperature Sensor B Circuit High

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. P01BC means the signal of sensor B sits near the reference voltage – it would report very cold oil; typically an open circuit, unplugged connector or short to voltage. Thresholds are presumably similar to sensor A (GM above 450 kΩ after 20 s of running), but are not documented for B. 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

Symptoms

• Check engine light on (depending on manufacturer)
• Oil temperature shows minimum
• Usually no driving symptoms

Repair estimate

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

Parts involved

Related codes

References: law.cornell.edu, gsi.ext.gm.com, en.wikipedia.org.