What it means
Intermittent signal from engine oil temp sensor B. 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 provides an oil-temperature signal that the control module monitors over time. This intermittent/erratic code sets when that signal from sensor B briefly drops out or changes unpredictably, often as a loose connection or vibrating harness interrupts contact.
Common causes
Most likely first.
- Connector loose or corroded
- Connector with intermittent contact under vibration
- Harness routed against vibrating component
Symptoms
- Check-engine light may come on intermittently
- Oil temperature reading may fluctuate or drop out
How to diagnose it
- Check freeze-frame data and scan-tool history for when sensor B's reading dropped out, and watch its live value for sudden jumps while the engine runs.
- Inspect sensor B's connector for looseness, corrosion, moisture, damaged seals, or terminals that do not grip securely.
- Trace sensor B's harness for rubbing, strain, or contact with a vibrating component that could interrupt the signal.
- Monitor the live reading while gently moving the connector and harness, then check whether normal engine vibration reproduces the dropout.
- Test sensor B's wiring and connector continuity while flexing the harness, and compare the sensor's response with the manufacturer's specification.
Common fixes
- Secure a loose sensor B connector and route its harness away from vibration or rubbing.
- Clean serviceable terminals and replace damaged connector seals.
- Repair intermittent wiring or replace loose, corroded, or damaged terminals.
- Replace sensor B if its signal remains erratic with a sound connector and harness.
Can I keep driving?
If the engine runs normally and no oil-pressure warning is present, short, gentle driving may be possible, but the oil-temperature reading could disappear without warning. 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.