P0379 Code Meaning and Next Steps

First checks take 10 minutes for basic checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The check-engine light is flashing or the engine is shaking badly.
!The vehicle is stalling, struggling to accelerate, or obviously running rough.

If the light is steady and the vehicle still drives normally: Maybe, but only for a very short distance if the engine still runs smoothly.

What to check first

Step-by-step checks

1
Free - no tools
Check whether the engine has a no-start, stall, or rough-running symptom at the same time
2
Free - no tools
Inspect the timing sensor connector and harness for damage or disconnection
3
Basic tool needed
Look for metal debris near the sensor or signs of a broken target wheel
4
Basic tool needed
If scan data is available, confirm whether the signal is truly gone or just missing under certain conditions
5
Basic tool needed
Check whether the code appeared after timing work or sensor replacement

If the code returns

-If no pulses are present at the sensor, sensor or circuit failure becomes more likely.
-If the sensor tests okay, inspect the target wheel and mechanical drive path.
-If the code returns after repair, recheck connector fit and harness routing.

Background

What this code means

P0379 is a generic OBD-II code for a timing reference signal with no pulses.

If the controller cannot see any pulse pattern at all, the problem is often a failed sensor, an open circuit, or a mechanical issue with the target wheel.

Diagnosis

Common causes

Most common

Failed timing sensor

The sensor may no longer generate a usable pulse signal.

Common

Open circuit or disconnected harness

A break in the circuit can remove the signal completely.

Common

Damaged target wheel

The reference source may no longer be able to create pulses.

Possible

Connector damage

A loose or corroded connector can behave like an open circuit.

Avoid these mistakes

What not to do

xDo not replace the ECU first if the sensor or target wheel is visibly damaged.
xDo not keep cranking a no-start engine without checking the timing signal path.

Parts

Parts that may need replacing

PartTypical costNotes

Timing sensor$40-$180Worth checking when the pulse signal is missing entirely.

Connector or wiring repair$50-$250Useful when the signal path is open or disconnected.

Target wheel or reluctor repair$200-$900Relevant when the reference pattern is mechanically gone or damaged.

Related OBD codes

P0376

P0376 means the engine timing reference high-resolution signal has too many pulses.

P0377

P0377 means the engine timing reference high-resolution signal has too few pulses.

P0378

P0378 means the engine timing reference high-resolution signal is intermittent or erratic.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0379 was seeded from dtcdb and then expanded around no-pulse timing reference faults, with emphasis on sensor, wiring, and target-wheel checks.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0379 - The Engine Timing Reference High-resolution Signal Has No Pulses