P2321Ignition Coil H Primary Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- With P2321 the engine module has seen the switching line of coil H pulled to ground; on a V8 coil H is the final one, on a V10 it is number eight. GM's 2019 tables, which label the code as cylinder 8, carry it for the LT5 Corvette and the L84 5.3-litre truck engine: a Type B fault after 50 bad readings in 63 samples taken every 100 ms with the system above 11 V. For 2014 Silverado and Sierra 1500 trucks with the L83 engine, GM information PIP5147 lists P2321 among the coil codes and advises checking the coil plugs for water or discoloured terminals, swapping the coil to another cylinder and adding dielectric grease. Ford lists it as well in its coil driver group. An open circuit on the same coil is P0358.
- What you may notice
- Check engine light on
- Cylinder 8 misfires or drops out
- Rough idle and weaker pulling power
- Likely causes
- LikelyWater ingress or corrosion in the coil H connector (GM PIP5147)
- PossibleCoil H with internal short
- PossibleCoil H control wire chafed through to ground
- RareCoil driver stage in the engine module damaged
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.