What it means
The ECM detects a range/performance fault on the crankcase pressure sensor b circuit. Reading cannot be used reliably for control.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Crankcase pressure sensor B measures crankcase pressure for the ECM's engine and ventilation control calculations. This range/performance code sets when the sensor B signal is electrically present but falls outside the expected range or does not change as expected.
Common causes
Most likely first.
- Sensor characteristic drifted
- Sensor mounting displaced
- Sensor element aged beyond calibration window
Symptoms
- Check-engine light
- Rough or uneven idle
- Lower fuel economy
How to diagnose it
- Review freeze-frame data and live sensor B pressure to see the engine conditions when the value became implausible.
- Inspect sensor B's mounting, connector, and nearby harness for displacement, contamination, loose fit, or damage that could distort its reading.
- Compare sensor B's output under changing engine conditions with the manufacturer's expected response and specifications.
- Check the sensor B reference, ground, and signal wiring for resistance, shorts, or unstable connections using the wiring diagram.
- If installation and wiring are correct but the reading remains out of range, test or replace sensor B and confirm the code stays cleared.
Common fixes
- Secure crankcase pressure sensor B correctly in its mounting.
- Clean and reseat the sensor B connector and repair any damaged wiring.
- Replace sensor B if its output has drifted beyond the manufacturer's specified range.
- Clear the code and confirm the sensor reading tracks changing engine conditions.
Can I keep driving?
A short gentle drive is generally reasonable if the engine remains stable, but avoid extended driving if idle becomes rough or fuel use rises. The inaccurate sensor reading can impair engine control and should be diagnosed soon.
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.