P0374 Timing Reference High Resolution Signal A No Pulses

P0374 indicates no pulses from Timing Reference High Resolution Signal A. The controller is missing an expected high-resolution timing reference input.

Code details

Generic OBD-II · P0

System: Ignition / Misfire
Code type: Generic (SAE / ISO controlled)
Standard: SAE J2012 / ISO 15031-6

Diagnostic boundary

A diagnostic trouble code reports that a monitored test failed. It does not prove one specific part is bad, and manufacturer logic can add vehicle-specific conditions.

Do not keep cranking a no-start with P0374 until the missing timing reference source is located.

Symptoms of P0374

Rough idle, shaking, or a stumble under acceleration.
A flashing check-engine light during an active misfire.
Power loss and higher fuel consumption.

Common causes of P0374

Worn spark plugs, ignition coils, or plug wires.
Fuel-delivery problems — injectors, pressure, or a lean/rich mixture.
Vacuum leaks, low compression, or a mechanical fault in that cylinder.

Useful checks before replacing parts

Check scan-tool RPM, high-resolution signal A status, crank signal status, cam sync, spark and injector enable, and freeze-frame data.
Inspect sensor supply, ground, signal continuity, connector condition, damaged trigger wheel, failed pickup, and controller input pins.
Verify the signal at the sensor and at the controller to determine whether the failure is sensor, harness, trigger, or module related.

Related OBD-II codes

These nearby ignition / misfire entries can help compare wording and pin down the fault area.