OBD-II Fault Code

P0320: Ignition/Distributor Engine Speed Input Circuit Malfunction

Meaning, symptoms, likely causes, diagnostic checks and repair guidance for P0320.

System family

Powertrain

Generic/SAE

Repair category

Electrical circuit / sensor

Use this category to narrow your checks before replacing parts.

Severity

Medium

Severity is a general guide. Confirm with scan-tool data and vehicle symptoms.

What P0320 usually means

Ignition/Distributor Engine Speed Input Circuit Malfunction.

Common symptoms

Check Engine light; Poor drivability or reduced fuel economy depending on fault

Likely causes

Faulty related sensor/actuator; Wiring or connector issue; Poor ground/power supply; Control module fault is possible but less common

Diagnostic checks

Scan all modules and record freeze-frame data before clearing codes; Check battery voltage and related fuses

Repair guidance

Repair wiring/connector/fuse issues first; Replace the related sensor/actuator only after testing confirms failure; Use OEM service manual for brand-specific procedures

Verification after repair

Clear code, road-test through the same drive condition, then rescan

Note: Confirm vehicle make/model/year because manufacturer-specific codes can vary. A DTC identifies a circuit or system condition, not always the failed part.