P0355Ignition Coil E Primary Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- Modern engines have one coil-on-plug ignition coil per cylinder, with the output stage either in the engine module or in the coil itself. P0355 monitors the primary control circuit of coil E – the line from the engine module to the coil or its built-in output stage – for an open circuit or high resistance. GM's module measures the voltage with its low-side driver off and flags an open circuit above 30 kΩ in 50 of 63 samples (2018 engines in the first trip, older ones after two); Ford checks continuously within 1 s, expecting a primary-current feedback for every ignition command, and shuts off injection to that cylinder for 30 s at a time. Short circuits and the secondary side have their own codes (P2300 ff). Coil E usually serves cylinder 5, but the assignment is up to the manufacturer.
- What you may notice
- Check engine light on
- Misfire and rough running on cylinder 5, often also P0305
- Loss of power, jerking under load
- Cylinder shut off (injection off), risk to the catalyst if driven on
- Likely causes
- LikelyIgnition coil E faulty (output stage in the coil or primary winding open)
- LikelyConnector at the coil corroded, loose or with a spread pin
- PossibleControl, supply or ground wire open or chafed
- RareFuse or relay of the coil supply (then usually several codes)
- RareDriver in the engine module faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €40 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.