What it means
A general electrical fault is reported on rough-road sensor B — used to gate misfire detection so that engine vibration from rough roads is not misclassified as misfire.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
Rough-road sensor B provides a separate input the controller can use to account for road-induced vibration during misfire monitoring. P0319 identifies an electrical fault in sensor B’s signal circuit, so diagnosis should follow the B circuit and its connections rather than sensor A’s.
Common causes
Most likely first.
- Rough-road sensor B fault
- Open, shorted, or damaged sensor wiring
- Loose or corroded sensor connector
- Control module or configuration fault
Symptoms
- Check engine light on
- Misfire warning or reduced engine performance
- Rough running may be reported or misfire detection may be limited
How to diagnose it
- Check freeze-frame data and related chassis or communication codes to establish when the sensor B circuit fault occurred.
- Identify rough-road sensor B from the vehicle’s wiring information and inspect its connector and harness for damage, corrosion, or a loose fit.
- Review scan-tool data for sensor B and see whether its signal is missing or abnormal when the fault is present.
- Test sensor B’s power, ground, signal, and wiring continuity as applicable, using the manufacturer’s specification for comparison.
- If the circuit checks out, test sensor B and the receiving module or network according to vehicle-specific service information.
Common fixes
- Reconnect or clean a loose or corroded sensor B connector.
- Repair an open, shorted, or damaged wire in the sensor B circuit.
- Replace rough-road sensor B if testing confirms it has failed.
- Repair a verified module or communication problem after checking the sensor B circuit.
Can I keep driving?
P0319 can reduce the reliability of misfire monitoring, but the code alone does not mean the engine is misfiring. If the engine runs normally, cautious driving is usually reasonable; stop if the light flashes or severe roughness or power loss develops.
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.