Engine

P0392 — Camshaft Position Sensor 'B' Circuit Low (Bank 2)

Severity: medium Drive with care, to a shop

What P0392 means

The engine control unit detected a voltage that is too low in the circuit of camshaft position sensor B on bank 2. The ECU uses this signal to know the camshaft phase and to time fuel injection, spark and variable valve timing. When the signal drops out or stays near ground, the ECU loses part of that information and sets the code.

Symptoms

  • Check Engine light on
  • Rough or uneven idle
  • Hesitation and reduced power
  • Hard starting or long cranking
  • Engine stalling
  • Worse fuel economy

Possible causes

  1. Failed bank 2 camshaft position sensor B
  2. Open or damaged sensor wiring harness
  3. Signal wire shorted to ground
  4. Corroded or loose sensor connector
  5. Poor connection at the ECU connector
  6. Damaged or misaligned camshaft reluctor (trigger) wheel
  7. Faulty ECU (rare)

How to diagnose

  1. Scan all codes and freeze frame data, and check for other camshaft or crankshaft sensor codes.
  2. Find sensor B on bank 2 for your engine using service information.
  3. Inspect the sensor, connector and harness for chafing, oil, heat damage and corrosion.
  4. Measure the sensor's supply voltage and ground at the connector and compare with the wiring diagram.
  5. Test the signal wire for an open circuit or a short to ground.
  6. Check the sensor output with a scope or per spec while cranking.
  7. Inspect the reluctor wheel and sensor air gap, and confirm correct installation.
  8. Clear the code after the repair and verify it does not return.

Common fixes

  • Replace camshaft position sensor B on bank 2
  • Repair or replace the damaged harness or connector
  • Clean and secure the connector, applying dielectric grease if appropriate
  • Replace a damaged reluctor wheel
  • Reflash or replace the ECU only if everything else checks out

Questions and answers

What does P0392 mean?

It means the signal from camshaft position sensor B on bank 2 is too low. The cause is most often the sensor itself or its wiring.

Can I drive with P0392?

Only briefly and to a repair shop. The engine may stall or fail to start, and misfires can harm the catalytic converter.

Will replacing the sensor fix it?

Not always. Check the wiring, connector and sensor supply first, because a short to ground can ruin a new sensor too.

This is general information about the code. The meaning can differ between makes and models: a scan tool and the repair manual for your car will show the exact cause.