OBD2 P0379

Severity

Summary

Code P0379 indicates a problem with the high-resolution timing reference signal 'B', typically related to issues with engine position sensors or wiring. This code is set when the Powertrain Control Module (PCM) detects no pulses from an engine position sensor.

Symptoms

• Stored trouble code and illuminated warning light
• Hard starting condition in some cases
• Misfires throughout the engine’s operating range, often accompanied by additional misfire codes
• No-start condition

Common Causes

• Damaged or disconnected wiring and connectors
• Defective engine position sensors (crankshaft or camshaft)
• Excessive air gap between sensor and reluctor wheel
• Clogged reluctor wheels with dirt, mud, etc.
• Failed PCM

Diagnosis

1. Record all codes and freeze frame data
2. Identify and locate engine position sensors and associated wiring
3. Inspect for damaged, burnt, shorted, disconnected, or corroded wiring/connectors
4. Check air gap between sensor and reluctor wheel; clean and reset if necessary
5. Perform resistance, continuity, ground, and reference voltage tests on relevant wiring
6. Test the engine position sensor itself

Fixes

• Replace damaged or defective wiring/connectors
• Clean and reset air gap between sensor and reluctor wheel
• Replace faulty engine position sensors (crankshaft or camshaft)

FAQ