P0320
Ignition/Distributor Engine Speed Input Circuit Malfunction
The engine computer cannot reliably see the engine speed signal it needs for ignition and fuel control. Depending on the vehicle, this may come from a crankshaft sensor, distributor input, ignition module, or related wiring. The engine may stall, run poorly, or not start at all.
- SEV
- 4/5
- DRIVE
- NO
- DIY
- $20-$180
- SHOP
- $120-$600
Quick answer
AI-CITATION READYWhat it means
Can you drive with it?
Most common causes
- Faulty crankshaft position sensor, distributor pickup, or related engine speed input sensor
- Damaged wiring, connector, or poor terminal contact in the engine speed input circuit
- Faulty ignition module or distributor-related input problem on applicable vehicles
Typical repair cost
DIY usually runs $20-$180. Typical shop repair lands around $120-$600, depending on the root cause.
01 / Definition
P0320 means the PCM detected a fault in the engine speed input circuit used for ignition and timing reference. On some vehicles this involves a distributor or ignition module input, while on others it overlaps with crankshaft speed signal monitoring. If the signal is missing, erratic, or implausible, the PCM may lose spark timing, injector timing, or engine synchronization and can cause stalling or a no-start condition.
02 / Drive status
No — get it towed. Do not keep driving if the engine stalls, cranks without starting, or runs badly. Loss of engine speed input can cause a sudden stall or no-start and may leave you stranded.
03 / Symptoms
- Check engine light on
- Engine stalls while driving
- Engine cranks but will not start
- Hard starting
- Rough running or misfire
- Poor acceleration
- Tachometer may drop to zero or act erratically
04 / Causes
| 1 | Faulty crankshaft position sensor, distributor pickup, or related engine speed input sensor | high |
|---|---|---|
| 2 | Damaged wiring, connector, or poor terminal contact in the engine speed input circuit | high |
| 3 | Faulty ignition module or distributor-related input problem on applicable vehicles | medium |
| 4 | Power supply, ground, fuse, or relay issue affecting the sensor or ignition input circuit | medium |
| 5 | Reluctor wheel, tone ring, or mechanical timing problem affecting the speed signal | medium |
| 6 | PCM input or internal module fault | low |
05 / Diagnostic sequence
- 01Check for related crankshaft, camshaft, ignition module, or misfire codes and record freeze-frame data.
- 02Inspect the engine speed input sensor or distributor-related connector and wiring for damage, oil intrusion, corrosion, looseness, or rubbed insulation.
- 03Verify power, ground, and signal circuit integrity with a wiring diagram and multimeter.
- 04Use a scan tool or oscilloscope to confirm the engine speed signal is present and stable while cranking and running.
- 05Inspect the reluctor wheel, tone ring, distributor pickup, or related timing components if the signal is intermittent or implausible.
- 06Check the ignition module or distributor input path on vehicles that use those components.
- 07If external circuits test good, inspect PCM inputs and related fuse or relay circuits before replacing major parts.
06 / Repairs
| 1 | Repair damaged wiring, connectors, or terminals in the engine speed input circuit | $20-$200 |
|---|---|---|
| 2 | Replace the crankshaft sensor, distributor pickup, or related engine speed input sensor if testing confirms failure | $30-$180 |
| 3 | Repair ignition module, distributor, or related input hardware on vehicles equipped with those components | $80-$400 |
| 4 | Repair fuse, relay, or power and ground supply issues affecting the circuit | $20-$200 |
| 5 | Replace damaged reluctor or timing components if they are corrupting the engine speed signal | $100-$900 |
| 6 | Diagnose PCM input faults only after all sensors, wiring, and mechanical checks pass | $150-$900 |
07 / Related codes
08 / FAQ
Can P0320 cause a no-start?
Yes. If the PCM cannot see a valid engine speed signal, it may not allow proper spark or fuel control.
Is P0320 the same as a crankshaft sensor code?
Not exactly. It is broader and can involve crankshaft input, distributor input, ignition module input, or related engine speed circuitry depending on the vehicle.
Can a bad ignition module cause P0320?
Yes. On vehicles that use an ignition module or distributor-based speed input, that hardware can trigger P0320.
Will clearing the code fix it?
No. If the engine speed input fault is still present, the code will return and the engine may still stall or fail to start.
09 / Source and method
- DATA BASIS
- OBD-II REFERENCE + OBD2.HELP
- METHOD
- STATIC VALIDATION
- SAFETY
- INFORMATIONAL
This page combines OBD-II diagnostic reference data with OBD2.help generated diagnostic guidance for code meaning, likely causes, and repair direction.
Publishing uses deterministic schema and build validation, plus manual spot checks on representative pages before release.
Safety-critical diagnosis and repairs should be confirmed with a qualified mechanic, especially when the vehicle is misfiring, overheating, or losing power.