Faulty camshaft position sensor B on bank 2; Damaged, chafed or shorted wiring in the sensor signal or supply circuit, such as a short to earth or open circuit; Corroded, loose or contaminated connector at the sensor or control unit; Oil contamination or leakage into the sensor connector or wiring, often from a leaking valve cover or seal; Damaged or incorrectly fitted reluctor or trigger wheel, or timing misalignment, affecting the signal; Fault in the engine control unit or its sensor supply.

P0392

Camshaft Position Sensor B Circuit Low Bank 2.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
3: AreaIgnition system or misfire
92: FaultThe specific fault in that area

What it means

P0392 means the engine control unit has detected a signal voltage that is too low on the circuit for camshaft position sensor B on bank 2. The sensor signal is stuck near zero volts or below the expected range, which can point to a short to earth, an open circuit, a missing supply or a faulty sensor. Which camshaft the 'B' sensor monitors (intake or exhaust) depends on the engine, so check the model-specific information.

Symptoms

Engine cranks but is slow to start or fails to start
Malfunction indicator lamp on
Rough running or misfiring
Loss of power or reduced performance, possibly in limp mode
Poor fuel economy
Variable valve timing faults logged alongside or reduced valve timing function

Possible causes

Faulty camshaft position sensor B on bank 2likely
Damaged, chafed or shorted wiring in the sensor signal or supply circuit, such as a short to earth or open circuitlikely
Corroded, loose or contaminated connector at the sensor or control unitlikely
Oil contamination or leakage into the sensor connector or wiring, often from a leaking valve cover or sealpossible
Damaged or incorrectly fitted reluctor or trigger wheel, or timing misalignment, affecting the signalpossible
Fault in the engine control unit or its sensor supplyrare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting engine speed, temperature and conditions when the fault set
Confirm which sensor is bank 2 sensor B on this engine using model-specific information, as the layout varies
Visually inspect the sensor, its wiring and connector for heat damage, chafing, oil contamination and corrosion
Check the sensor is secure, correctly seated and the mounting and air gap are undamaged
Measure the sensor supply, earth and signal voltages at the connector against the manufacturer's specification
Test the wiring between sensor and control unit for continuity, short to earth and short to supply with the circuit isolated
View the live sensor signal while cranking, or use an oscilloscope, and compare it with the crankshaft signal
Check the trigger wheel and the cam timing if the signal is present but implausible, following model-specific procedures

How to fix

Replace the camshaft position sensor if it fails electrical or signal tests
Repair or replace damaged wiring, and fit a new connector or terminals where corroded or loose
Clean and dry the connector, and fix any oil leak that is contaminating the wiring or sensor
Correct or replace a damaged trigger wheel and reset the cam timing to specification if it is found out
Have the control unit tested and repaired or replaced only if supply and wiring are confirmed good

Can I keep driving?

Medium severity

The car may run with reduced performance or in limp mode, and could stall or fail to restart, so it should be repaired soon. Avoid long journeys or heavy loads until it is fixed, because the fault can worsen and affect drivability.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.