P0320 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
Check whether the engine cranks but does not start, or starts and then dies again
2
Free - no tools
Inspect the crank sensor or distributor connector for heat damage, corrosion, or a loose fit
3
Basic tool needed
Look for recent ignition work that may have left a connector unplugged or a wire pinched
4
Basic tool needed
If scan data is available, confirm whether engine speed disappears while cranking or driving
5
Basic tool needed
If the tachometer drops out, that is a useful clue to the speed-signal side

If the code returns

-If the speed signal is missing entirely, the crank sensor or its wiring moves up the list fast.
-If the signal is intermittent, a heat-related wiring fault or ignition module problem becomes more likely.
-If the engine runs fine after a repair, retest before replacing any additional parts.

Background

What this code means

P0320 is a generic OBD-II crankshaft-speed or engine-speed input code for the ignition/distributor or engine speed input path.

On older systems this can come from the distributor or ignition module, while on newer systems it often traces back to the crankshaft sensor and its wiring.

A hard no-start, sudden stall, or intermittent cut-out can happen if the ECU loses the engine-speed signal.

Diagnosis

Common causes

Most common

Failed crank or distributor speed sensor

The ECU may lose the engine-speed signal completely.

Common

Ignition module fault

Older systems can lose the reference signal through the module.

Common

Connector or harness issue

Heat damage or a loose connector can cut the signal.

Possible

Tone wheel or trigger issue

A damaged trigger path can confuse the speed signal.

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 speed signal is actually missing.

Ignition module or pickup sensor$60-$300Worth checking on older distributor-based systems.

Connector pigtail repair$15-$90Relevant if the connector is heat damaged or loose.

Related OBD codes

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.

P0323

P0323 usually means the engine-speed input signal is intermittent.

P0335

P0335 usually means the crankshaft position sensor A circuit is not behaving correctly.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0320 was expanded around common engine-speed input faults, including crank sensor failure, ignition module 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

P0320 - P0320 Usually Means the Ignition or Engine-speed Input Circuit Is Not Behaving Correctly