P0373 — Timing Reference High Resolution Signal A Too Few Pulses
Drive with caution — fix soon.
What P0373 means
This code means the engine control module is seeing fewer high-resolution timing pulses than it expects from the 'A' reference sensor, usually a crankshaft or camshaft position sensor. It typically points to a failing sensor, damaged wiring, or a problem with the reluctor ring (the toothed wheel the sensor reads). It's usually fixable by replacing the sensor or repairing wiring, without major engine work.
Common symptoms
- Check engine light is on
- Engine hesitates or stumbles while driving
- Hard starting or longer cranking
- Rough idle or slight engine shaking
- Occasional stalling
Common causes
- Failing crankshaft or camshaft position sensor
- Damaged or corroded sensor wiring or connector
- Damaged reluctor/tone ring teeth
- Excessive air gap between sensor and ring
- Faulty engine control module (rare)
Typical repair cost
$150 – $450
Varies by vehicle and root cause.
Frequently asked questions
Can I keep driving with a P0373 code?
For short trips, usually yes, but you shouldn't rely on it long-term. If the engine stumbles, hesitates, or is hard to start, get it checked promptly since it could leave you stranded.
How much does it cost to fix a P0373 code?
Most repairs run between $150 and $450. A simple sensor replacement is on the lower end, while wiring repairs or reluctor ring issues can push the cost higher.
Is a P0373 code serious?
It's moderately serious. It won't usually damage your engine, but it can cause poor running and unexpected stalling, so it's best to address it soon.
What does 'too few pulses' mean for P0373?
It means the timing sensor is sending fewer signal pulses than the computer expects per engine revolution, often due to a worn sensor, bad wiring, or damaged teeth on the trigger wheel.