P0358
Ignition Coil "H" Primary/Secondary Circuit
- Severity
- High
- Driving
- Short journeys only
A fault in the primary or secondary circuit of ignition coil "H". That coil is not firing its cylinder properly, so expect a misfire. The coil letter is the manufacturer's designation and does not necessarily correspond to the cylinder number - the vehicle's own documentation says which is which, and a misfire code stored alongside will usually name the cylinder directly.
Possible causes
- CommonFailed ignition coil
- CommonWorn or fouled spark plug making the coil work harder until it fails
- CommonCracked coil boot, or oil in the plug well tracking the spark to earth
- CommonCorroded or damaged connector at the coil
- PossibleWiring fault between the module and the coil
- RareFailed control module driver
What you might notice
- Misfire - the engine shaking, especially at idle
- Loss of power and hesitation
- Check engine light on, or flashing
- Poor fuel economy
- Smell of unburnt fuel from the exhaust
What to check, in order
- Read all codes. A misfire code for a specific cylinder alongside this one identifies which coil to look at first.
- Swap the suspect coil with one from a neighbouring cylinder and see whether the misfire follows it. This is the single most effective test available and it costs nothing - but only do it on engines where the coils are genuinely interchangeable.
- Look at the spark plug for that cylinder. A worn plug makes the coil work far harder, and fitting a new coil onto a worn plug often just kills the new coil too.
- Check the plug well for oil. A leaking cam cover gasket fills the well and the spark tracks to earth through the oil rather than jumping the plug gap.
- Inspect the coil boot for cracks and carbon tracking.
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