P0372

P0372: Timing Reference High Resolution Signal "A" Too Few Pulses

Quick answer: P0372 means the engine computer has detected a "too few pulses" fault on the high-resolution timing reference signal.

Driving: Can cause stalling. Have it diagnosed before relying on the vehicle.

Read P0372 on your phone OBDAssistant reads codes and live data through a Bluetooth OBD2 adapter.

What P0372 means

P means powertrain (engine and transmission). The 0 marks a generic code defined by SAE, so the same number means the same thing across makes. The third character, 3, places it in the ignition system or misfire subsystem; the last two digits identify the specific fault.

Some engines use a high-resolution timing signal (many pulses per revolution) alongside a low-resolution reference for precise ignition and injection timing. The engine computer counts pulses between reference events; too many, too few or erratic pulses set these codes.

The letter "A" distinguishes between two or more of the same component on one vehicle. Which physical part is "A" is set by the manufacturer, so confirm it in the service information before replacing anything.

What “Too Few Pulses” means here

Fewer pulses arrived between reference events than expected: some are being missed. Look at sensor air gap, a damaged target wheel, a weak sensor or a poor connection.

What you may notice

Symptoms depend on the vehicle and on how the module responds to the fault. Any of these can accompany P0372:

  • Hard starting
  • Misfire or rough running
  • Stalling

Where to start diagnosing P0372

  1. Inspect the sensor connector and harness, particularly for interference from nearby ignition wiring.
  2. Check the sensor and its target wheel for damage.
  3. Confirm the signal with a scope where possible.

Clear the code only after recording freeze frame data: it shows the engine speed, load and temperature at the moment the fault set, which is often the best clue to reproducing it.

Live data to watch

These standard OBD2 values relate to P0372. Support varies by vehicle; a value your car does not report will simply be missing.

ValueWhat to look for
Engine RPM (PID 0x0C)Look for dropouts.

Related codes

Codes from the same high-resolution timing reference signal family. If several are stored together, the shared part — wiring, a common reference voltage, or the component itself — is the place to start.

CodeDefinition
P0370Timing Reference High Resolution Signal "A"
P0371Timing Reference High Resolution Signal "A" Too Many Pulses
P0373Timing Reference High Resolution Signal "A" Intermittent/Erratic Pulses
P0374Timing Reference High Resolution Signal "A" No Pulse
P0375Timing Reference High Resolution Signal "B"
P0376Timing Reference High Resolution Signal "B" Too Many Pulses
P0377Timing Reference High Resolution Signal "B" Too Few Pulses
P0378Timing Reference High Resolution Signal "B" Intermittent/Erratic Pulses

Further reading

Frequently Asked Questions

What does P0372 mean?

P0372 is the generic SAE J2012 code for "Timing Reference High Resolution Signal "A" Too Few Pulses". In plain terms, it means the engine computer has detected a "too few pulses" fault on the high-resolution timing reference signal.

Can I keep driving with P0372?

Can cause stalling. Have it diagnosed before relying on the vehicle.

What should I check first for P0372?

Inspect the sensor connector and harness, particularly for interference from nearby ignition wiring.

Definition source: SAE J2012 / ISO 15031-6 generic DTC definitions. This is the generic meaning that applies across makes; a manufacturer can define a code more narrowly or add its own sub-codes, so confirm against the service information for your vehicle before replacing parts. Written by the OBDAssistant engineering team — see our editorial policy.