Damaged or chipped reluctor wheel (tone ring) on the crankshaft or camshaft; Faulty crankshaft or camshaft position sensor; Wiring harness damage such as chafed wires, loose connectors, or corrosion; Electrical interference from aftermarket ignition components or poor grounding; Metal debris stuck to the sensor tip or reluctor wheel; Worn timing chain or belt causing erratic signal; Engine control module (ECM) internal fault (rare)

DTC codes / P03xx · Ignition system and misfire / P0371

P0371Timing Reference High Resolution Signal 'A' Too Many Pulses

Q: What does code P0371 mean?

Timing Reference High Resolution Signal 'A' Too Many Pulses. P0371 means the engine computer detected too many pulses on the high-resolution timing reference signal 'A' circuit, which is used to precisely locate the crankshaft or camshaft position. The computer expects a specific number of pulses per revolution and flags the code when the count exceeds that threshold, indicating a signal integrity problem.

P0371 means the engine computer detected too many pulses on the high-resolution timing reference signal 'A' circuit, which is used to precisely locate the crankshaft or camshaft position. The computer expects a specific number of pulses per revolution and flags the code when the count exceeds that threshold, indicating a signal integrity problem.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Rough idle or misfire due to inaccurate timing
Engine may stall or hesitate during acceleration
Difficulty starting or extended cranking
Reduced fuel economy and power output
In some cases, the engine may enter limp mode

Common causes, most likely first

Damaged or chipped reluctor wheel (tone ring) on the crankshaft or camshaft
Faulty crankshaft or camshaft position sensor
Wiring harness damage such as chafed wires, loose connectors, or corrosion
Electrical interference from aftermarket ignition components or poor grounding
Metal debris stuck to the sensor tip or reluctor wheel
Worn timing chain or belt causing erratic signal
Engine control module (ECM) internal fault (rare)

How to diagnose and fix it

Inspect the sensor and reluctor wheel for physical damage, debris, or misalignment
Check the wiring and connectors for the high-resolution timing sensor circuit for continuity and corrosion
Measure sensor resistance and compare to manufacturer specifications
Use an oscilloscope to verify the signal waveform for extra pulses or noise
Check for aftermarket accessories that may introduce electrical interference and temporarily disconnect them
Replace the faulty sensor if tests indicate failure
If the reluctor wheel is damaged, replace it according to service procedures

Signal integrity checks before parts replacement

A common oversight is assuming the sensor is at fault when the reluctor wheel has a cracked or missing tooth that causes extra pulses.
Electrical noise from poorly routed aftermarket wiring or a failing alternator can mimic a faulty sensor and set this code.
The code can be set by a loose or corroded connector that intermittently adds resistance, so wiggle-testing the harness is essential.
On some engines, a stretched timing chain can cause the camshaft signal to have extra pulses relative to the crankshaft, triggering P0371.
Always clear the code and perform a road test to confirm the repair, as the fault may be intermittent and not immediately reappear.

Can I keep driving with P0371?

You can drive the vehicle cautiously to a repair shop, but avoid heavy acceleration or towing, as inaccurate timing can cause misfires and potential engine damage. If the engine runs poorly or stalls, stop driving and seek professional assistance.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.