P0393 Camshaft Position Sensor B Circuit High (Bank 2)

P0393 points to a high input condition in Camshaft Position Sensor B circuit on Bank 2. The controller sees the Bank 2 cam B signal stuck high or above range.

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 replace the sensor until wiring, ground, and reference-voltage faults have been ruled out.

Symptoms of P0393

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 P0393

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 cam sensor B Bank 2 signal voltage, reference voltage, ground path, freeze-frame RPM, and other high-input codes.
Inspect for open grounds, short-to-voltage faults, connector corrosion, damaged insulation, sensor contamination, and cam target problems.
Scope the cam B signal during cranking and running to confirm whether it toggles normally or remains biased high.

Related OBD-II codes

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