Code Definition

P0379 — Timing Reference High Resolution Signal B No Pulses

System: Powertrain  |  Type: Generic (OBD-II Standard)  |  Make: Generic

About P0379

P0379 is a generic (obd-ii standard) powertrain diagnostic trouble code. It belongs to the P-prefix family of codes, which covers engine, transmission, emissions, or fuel-system faults.

When P0379 is stored, the module has detected a signal or supply voltage higher than the expected operating range.

Scanning & clearing: A generic OBD-II scan tool will usually read and clear powertrain (P) codes. For live data, freeze-frame capture, and bi-directional tests you may need a more capable scan tool that supports the vehicle's ECM protocol.

Because P0379 is a generic OBD-II code, its base definition is shared across manufacturers. The specific diagnostic steps, reference values, and repair procedures can vary by vehicle, and the TaT Diagnostic Assistant includes verified procedures submitted by working technicians.

Code Information

The powertrain control module (PCM) sets this code when it fails to detect any pulses from the high-resolution timing reference signal 'B', which is typically generated by a secondary crankshaft or camshaft position sensor. A complete loss of signal prevents the PCM from accurately controlling ignition timing and fuel injection, potentially resulting in a no-start condition, engine stalling, or severe drivability issues.

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