What it means
Engine oil temp sensor B signal voltage above expected range. Wiring faults of this kind typically come from chafing, water ingress at connector seals, or pin push-back — a wiggle test on the harness while the code is active often confirms the location.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Engine oil temperature sensor B sends an electrical signal representing oil temperature to the control module. This circuit-high code means the module sees sensor B's signal above its expected electrical range, which can happen if the signal path is open or a wire is contacting a power source.
Common causes
Most likely first.
- Signal wire open
- Connector pins corroded - high contact resistance
- Supply wire pinched against B+ source
Symptoms
- Check-engine light on
- Oil temperature reading may be inaccurate or unavailable
How to diagnose it
- Review freeze-frame data and live oil-temperature sensor B data to see whether the reading is implausibly hot or unavailable.
- Inspect sensor B's connector and harness for an unplugged connector, broken wire, corrosion, backed-out pins, or insulation damaged near a power source.
- Check terminal fit and continuity through sensor B's signal wire, paying particular attention to an open circuit or a loose connector contact.
- With the live reading displayed, move the sensor B harness gently to check whether a broken connection makes the signal drop in and out.
- Test the signal wire for an open or short to power and verify the sensor's supply and ground against the wiring diagram and manufacturer's specification.
Common fixes
- Reconnect and secure a loose sensor B connector.
- Repair an open signal wire or damaged connector terminal.
- Repair wiring pinched against or shorted to a power source.
- Replace sensor B if it fails the manufacturer's electrical or response checks after circuit faults are corrected.
Can I keep driving?
If the engine runs normally and there are no oil-pressure warnings, limit driving and monitor the vehicle closely because the reported oil temperature may be wrong. Stop if an oil-pressure warning or signs of overheating appear.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.