P0394 Camshaft Position Sensor B Circuit Intermittent (Bank 2)

P0394 indicates an intermittent Camshaft Position Sensor B circuit on Bank 2. The Bank 2 cam B signal drops out or becomes unstable only under certain conditions.

Code details

Generic OBD-II · P0

System: Ignition / Misfire
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not rely on a stationary cold test for P0394 if the code sets during heat, vibration, or road load.

Symptoms of P0394

Rough idle, shaking, or a stumble under acceleration.
A flashing check-engine light during an active misfire.
Power loss and higher fuel consumption.

Common causes of P0394

Worn spark plugs, ignition coils, or plug wires.
Fuel-delivery problems — injectors, pressure, or a lean/rich mixture.
Vacuum leaks, low compression, or a mechanical fault in that cylinder.

Useful checks before replacing parts

Review hot-start behavior, stall history, cam-crank sync loss, freeze-frame RPM, VVT movement, and related intermittent cam or crank codes.
Inspect connector tension, harness flex points, oil intrusion, sensor mounting, target wheel condition, grounds, and wiring near heat sources.
Record cam signal data while heat-soaking, moving the harness, and road-testing to catch brief Bank 2 signal dropouts.

Related OBD-II codes

These nearby ignition / misfire entries can help compare wording and pin down the fault area.