Damaged wiring, poor connector contact or corrosion in the timing signal circuit; Faulty crankshaft or camshaft position sensor, or whichever sensor provides the high resolution signal on this model; Damaged, contaminated or misaligned reluctor or trigger wheel; Sensor power or earth supply fault, such as a blown fuse or poor earth; Incorrect mechanical timing, for example a jumped or worn timing belt or chain; Fault in the engine control unit or the module that processes the signal.

P0379

Timing Reference High Resolution Signal B No Pulses.

Generic
Powertrain
Generic code
High severity

How this code is built

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

What it means

P0379 is the generic code for no pulses on the high resolution timing reference signal B. The control unit expects a stream of pulses from a high resolution timing source, such as a crank or camshaft signal used for precise timing or misfire detection, and has seen none. Where this signal exists and what it is derived from depends on the vehicle and engine, and it is not used on every vehicle.

Symptoms

Engine management warning light on
Engine cranks but fails to start, or starts and stalls
Rough running or misfire
Poor performance or limp mode
Intermittent cutting out while driving
Other crank or cam signal codes stored alongside

Possible causes

Damaged wiring, poor connector contact or corrosion in the timing signal circuitlikely
Faulty crankshaft or camshaft position sensor, or whichever sensor provides the high resolution signal on this modellikely
Damaged, contaminated or misaligned reluctor or trigger wheelpossible
Sensor power or earth supply fault, such as a blown fuse or poor earthpossible
Incorrect mechanical timing, for example a jumped or worn timing belt or chainpossible
Fault in the engine control unit or the module that processes the signalrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, paying attention to engine speed and whether the engine was running when the code set
Check live data for engine speed while cranking to see whether the control unit sees a signal
Inspect the sensor wiring, connectors and mounting for chafing, oil contamination, water ingress and looseness
Check the relevant fuses and the sensor's supply voltage and earth against the manufacturer's data for that model
Test the sensor signal with an oscilloscope while cranking and compare it with a known good pattern for the engine
Inspect the trigger wheel for damage, debris or movement, and check it is seated correctly
Verify mechanical timing and the condition of the belt or chain if signals are present but implausible
Check for any applicable software update or technical bulletin for the model before considering the control unit

How to fix

Repair or replace damaged wiring and clean or renew corroded connectors
Replace the faulty position sensor with a correct specification part and check it is fitted with the right air gap
Replace or realign a damaged trigger wheel or reluctor
Restore the sensor supply or earth, including replacing any blown fuse once the cause is found
Correct the mechanical timing and replace worn drive components
Repair or replace the control unit only after all wiring and sensors are proven good

Can I keep driving?

High severity

Avoid driving the car if it is stalling, misfiring or in limp mode, as it could cut out without warning in traffic and risk damage. Have it diagnosed before further use.

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