What it means
Cam sensor B on bank 1 reads in range but plausibility check fails — slow response, drift, or signal does not match expected cam profile.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Camshaft Position Sensor B on bank 1 reports the position of that camshaft so the engine control module can compare cam timing with the crankshaft and manage valve timing and ignition. This code sets when the signal is present but its timing or response does not match the expected pattern.
Common causes
Most likely first.
- Sensor drift
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- Check engine light on
- Power loss especially in mid-rpm range
- Possible rough idle or stalling
- Increased fuel consumption
How to diagnose it
- Record freeze-frame data and compare live camshaft and crankshaft timing readings to see when the bank 1 Sensor B signal becomes implausible.
- Inspect Sensor B on bank 1 and its mounting for looseness, damage, contamination, or incorrect seating that could damp or distort the signal.
- Check the sensor connector and nearby wiring for corrosion, loose pins, oil intrusion, or damage that could affect the signal.
- Monitor the Sensor B signal while the engine runs and check whether it responds smoothly as engine speed changes.
- Test the sensor and its circuit against the manufacturer's specification, then investigate cam timing or mechanical causes if the signal remains implausible.
Common fixes
- Secure or correctly reseat a loose bank 1 Sensor B.
- Clean or repair corroded or loose connector terminals.
- Repair damaged wiring affecting the Sensor B signal.
- Replace Sensor B on bank 1 if it fails testing.
- Correct a verified cam timing or mechanical fault if the sensor and wiring pass.
Can I keep driving?
If the engine runs smoothly, limit driving and avoid hard acceleration until diagnosed; the timing error can worsen fuel economy and cause rough running or stalling. Stop if it stalls, loses substantial power, or becomes difficult to control.
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.