P0323 Code Meaning and Next Steps

First checks take 10 to 20 minutes for the first checks. No special tools are usually needed for the first checks.

Can you keep driving?

Stop driving if any of these apply

!The engine stalls, cranks without starting, or cuts out repeatedly.
!The tachometer drops out or the warning light flashes while driving.

If the light is steady and the vehicle still drives normally: Maybe, but only for a very short distance if the engine still runs smoothly.

What to check first

Step-by-step checks

1
Free - no tools
Inspect the crank sensor connector and harness for a loose plug, rubbed insulation, or heat damage
2
Free - no tools
Note whether the fault appears after a bump, heat soak, or long drive
3
Basic tool needed
If scan data is available, watch for the speed signal dropping out rather than staying flat all the time
4
Basic tool needed
Check whether recent repair work may have left the harness routed too close to heat or moving parts
5
Basic tool needed
A swap test or gentle harness wiggle can help confirm an intermittent fault

If the code returns

-If the signal drops out when warm or moving, wiring or sensor internal failure becomes more likely.
-If the fault clears after a harness repair, retest before replacing other parts.
-If the engine still cuts out after the signal looks stable, look for a second fault instead of assuming the code was the whole story.

Background

What this code means

P0323 is a generic OBD-II crankshaft-speed or engine-speed input code for the ignition/distributor or engine speed input path.

An intermittent speed signal often behaves like a heat or vibration problem, with the fault appearing and disappearing while the vehicle is driven.

The engine may stall briefly, hesitate, or restart after a cool-down when the signal comes back.

Diagnosis

Common causes

Most common

Loose or damaged connector

A bad pin fit can cut the signal intermittently.

Common

Heat-sensitive sensor

Some sensors fail only after they get hot.

Common

Chafed harness

Vibration can open and close the circuit.

Possible

Ignition module fault

Module-side failure can mimic an intermittent sensor.

Avoid these mistakes

What not to do

xDo not keep cranking a no-start engine for a long time if the speed signal is missing.
xDo not replace the ECU before checking the crank sensor, connector, and wiring.

Parts

Parts that may need replacing

PartTypical costNotes

Crankshaft position sensor$40-$180Relevant when the sensor itself is intermittent.

Ignition module$60-$300Worth checking on systems that route the signal through the module.

Connector pigtail repair$15-$90Relevant if the connector or pins are unstable.

Related OBD codes

P0320

P0320 usually means the ignition or engine-speed input circuit is not behaving correctly.

P0321

P0321 usually means the engine-speed input signal is out of normal range or performance.

P0322

P0322 usually means the engine-speed input signal is missing.

P0339

P0339 usually means the crankshaft position sensor A signal is intermittent.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0323 was expanded around common intermittent engine-speed signal faults, including heat-related sensor failure, connector issues, and wiring problems.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

P0323 - P0323 Usually Means the Engine-speed Input Signal Is Intermittent