P0321
Ignition/Distributor Engine Speed Input Circuit Range/Performance
- Severity
- High
- Driving
- Drive only to a garage
The ignition or distributor engine speed signal is present but implausible - erratic, or not matching what the module expects. On a high-mileage distributor this is often mechanical wear rather than an electrical fault.
Possible causes
- CommonFailed pickup or sensor inside the distributor
- CommonWorn distributor shaft or bearing
- CommonCorroded connector or damaged wiring
- PossibleFailed ignition module
- PossibleMoisture inside the distributor cap
What you might notice
- Engine will not start
- Cutting out while driving
- Rough running or misfire
- Rev counter erratic
- Check engine light on
What to check, in order
- Check inside the distributor cap for moisture, cracks and corroded contacts - the cheapest thing to eliminate.
- Check the connector and wiring at the distributor.
- Watch engine speed on the live data screen while cranking.
- Check the distributor shaft for play. A worn shaft moves the pickup out of position and produces an erratic signal that no new sensor will fix.
Read this code from your own car
Plug an ELM327 adapter into the OBD-II port under the dashboard. Pin16 reads every stored, pending and permanent code, explains each one like this page does — offline, with no account — and shows what the car recorded when the fault was set.
Where this code sits
P00xxP01xxP02xxP03xxP04xxP05xxP06xxP07xxP08xxP09xxP0AxxP0BxxP0CxxP0DxxP0ExxP0FxxP10xxP11xxP12xxP13xxP14xxP15xxP16xxP17xxP18xxP19xxP1AxxP1BxxP1CxxP1DxxP1ExxP1FxxP20xxP21xxP22xxP23xxP24xxP25xxP26xxP27xxP28xxP29xxP2AxxP2BxxP2CxxP2DxxP2ExxP2FxxP30xxP31xxP32xxP33xxP34xxP35xxP36xxP37xxP38xxP39xxP3AxxP3BxxP3CxxP3DxxP3ExxP3Fxx
Ignition system or misfire
P0300P0301P0302P0303P0304P0305P0306P0307P0308P0309P0310P0311P0312P0313P0314P0315P0316P0317P0318P0319P0320P0321P0322P0323P0324P0325P0326P0327P0328P0329P0330P0331P0332P0333P0334P0335P0336P0337P0338P0339P0340P0341P0342P0343P0344P0345P0346P0347P0348P0349P0350P0351P0352P0353P0354P0355P0356P0357P0358P0359P0360P0361P0362P0363P0364P0365P0366P0367P0368P0369P0370P0371P0372P0373P0374P0375P0376P0377P0378P0379P0380P0381P0382P0383P0384P0385P0386P0387P0388P0389P0390P0391P0392P0393P0394