HomeTrouble CodesP0374

P0374 — Timing Reference High Resolution Signal No Pulses

Generic OBD-II · all makesPowertrain (engine & transmission)

P0374 indicates the powertrain control module (PCM) is not receiving the expected high-resolution timing reference pulses from the crankshaft position sensor circuit. This signal is critical for precise fuel injection and ignition timing. Without it, the engine may fail to start or run poorly.

Symptoms

What causes it — most likely first

1. Failed crankshaft position sensor

The sensor itself is the most common failure point; internal open or short circuits prevent pulse generation.

2. Wiring or connector fault

Open circuits, short-to-ground, short-to-voltage, or corroded terminals in the sensor harness interrupt the signal.

3. Damaged or misaligned reluctor wheel

Missing teeth, excessive runout, or incorrect sensor-to-wheel air gap prevent reliable pulse detection.

4. Faulty camshaft position sensor (if used for high-resolution signal)

On some platforms the cam sensor provides the high-resolution reference; its failure can set P0374.

5. PCM internal driver or processing fault

Rare; the PCM's input circuit or signal processor may be defective, but only after sensor and wiring are verified good.

How it's diagnosed

  1. Visually inspect the crankshaft position sensor, connector, and harness for damage, corrosion, or loose terminals.
  2. Measure sensor resistance and compare to manufacturer specifications; check for AC voltage output while cranking.
  3. Use an oscilloscope to verify a clean, consistent square-wave pattern at the sensor and at the PCM connector.
  4. Confirm the reluctor wheel has no missing teeth and the sensor air gap is within specification.
  5. Perform continuity and voltage-drop tests on the signal, ground, and reference-voltage circuits between sensor and PCM.
  6. If all wiring and sensor tests pass, evaluate PCM input circuit with a known-good sensor or substitute PCM for confirmation.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Is the PCM usually the cause of P0374?

No. The PCM is rarely the root cause; the crankshaft position sensor, its wiring, or the reluctor wheel are responsible in the vast majority of cases.

Can a bad camshaft sensor set P0374?

On certain vehicles the camshaft position sensor provides the high-resolution reference; if that sensor fails, P0374 can be set even though the crank sensor is functional.

Will the engine run with P0374 active?

Typically the engine will not start or will stall immediately because the PCM cannot synchronize fuel and ignition events without the high-resolution signal.

Does clearing the code fix the problem?

Clearing the code only turns off the light; the underlying hardware fault remains and the code will return once the PCM detects the missing pulses again.