P0379

The P0379 code means the PCM has detected a timing reference high resolution signal "b" no pulses condition. This diagnostic trouble code relates to the ignition system, which is critical for proper combustion in the engine cylinders. When this code is triggered, one or more cylinders may not be firing correctly, leading to rough running, power loss, and potential catalytic converter damage if not addressed. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Noticeable engine vibration. Loss of power and acceleration. Check Engine Light (MIL) illuminated. Engine misfiring or running rough. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Faulty fuel injector(s). Vacuum leak in intake manifold. Failed ignition control module. EGR valve malfunction. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Connect an OBD-II scanner and read all stored trouble codes and freeze frame data. Inspect spark plugs for wear, fouling, or damage; replace if necessary. Test ignition coils using a multimeter or ignition coil tester. Check spark plug wires and boots for damage or arcing. Perform a compression test on the affected cylinder(s). If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Powertrain (P) collection on OBD Codes. We provide comprehensive, up-to-date information to help you find solutions quickly.