Loose, corroded or damaged connector at the engine speed or ignition signal sensor; Chafed, broken or intermittently open or shorted wiring in the speed signal circuit; Failing crankshaft position sensor, distributor pickup or related speed sensor that fails when hot or vibrating; Faulty ignition coil, ignition module or distributor internals feeding a poor speed signal; Poor power or earth supply to the sensor or ignition module; Damaged or contaminated reluctor wheel or trigger wheel, or excessive sensor air gap; Internal fault in the engine control unit.

P0323

Ignition/Distributor Engine Speed Input Circuit Intermittent.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
3: AreaIgnition system or misfire
23: FaultThe specific fault in that area

What it means

P0323 is the generic code for an intermittent fault in the ignition or distributor engine speed input circuit. The engine control unit has seen the engine speed signal from the ignition or distributor drop out, become erratic or disappear briefly while the engine was running. Because the fault comes and goes, it may not be present when the car is inspected. The exact signal source (distributor pickup, coil pack, crank or cam sensor) depends on the model and engine.

Symptoms

Intermittent misfire or hesitation
Engine cuts out or stalls occasionally, often restarting after a short wait
Rev counter flickering or dropping to zero while driving
Hard starting or extended cranking at times
Engine management warning light on, sometimes coming and going
Rough idle or loss of power under load

Possible causes

Loose, corroded or damaged connector at the engine speed or ignition signal sensorlikely
Chafed, broken or intermittently open or shorted wiring in the speed signal circuitlikely
Failing crankshaft position sensor, distributor pickup or related speed sensor that fails when hot or vibratinglikely
Faulty ignition coil, ignition module or distributor internals feeding a poor speed signalpossible
Poor power or earth supply to the sensor or ignition modulepossible
Damaged or contaminated reluctor wheel or trigger wheel, or excessive sensor air gappossible
Internal fault in the engine control unitrare

How to diagnose

Read all stored and pending codes and note the freeze frame data, including engine speed, load and temperature when the fault set
Check for related codes such as crank or cam sensor, misfire or ignition coil codes that point to the failing part
Visually inspect the sensor, ignition and distributor connectors and wiring for damage, corrosion, oil contamination, heat damage or chafing
With the engine running, wiggle the harness and connectors while watching live engine speed data for dropouts
Check the sensor and ignition module power supply and earth for voltage drop, using the manufacturer's wiring information
Inspect the sensor mounting, air gap and the reluctor or trigger wheel for damage or debris
Test the sensor signal with an oscilloscope, ideally when the fault is occurring, and compare it with a known good pattern for that engine
Check ignition coils, module and distributor components against the manufacturer's test procedure

How to fix

Clean, reseat or replace faulty connectors and terminals
Repair or replace damaged wiring in the speed signal, power or earth circuit
Replace the faulty crankshaft sensor, distributor pickup or related speed sensor
Replace the faulty ignition coil, ignition module or worn distributor components
Repair or replace a damaged reluctor wheel and set the sensor air gap where adjustable
Clear the code and road test to confirm the fault does not return

Can I keep driving?

Medium severity

The car may be driven carefully for a short time, but it can stall without warning, which is a safety risk in traffic. Have it checked soon, and avoid driving it if it is cutting out frequently.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.