P0355: Ignition Coil E Primary/Secondary Circuit
Key takeaways
- P0355 is an electrical code: the engine computer saw a bad signal in the circuit that fires ignition coil E, usually the coil for cylinder 5 on a V6, V8 or inline six.
- Drive only short, gentle trips; if the check engine light starts flashing or the engine shakes hard, stop.
- Check the coil connector, wiring and grounds first ($100–$250) before buying a coil ($120–$300).
- Ford has a bulletin for 2014–2016 F-250 and F-350 6.2L trucks where the coil connectors for cylinders 5 and 6 open up from rubbing on an intake part.
- GM notices for 2019–2021 Silverado and Sierra 1500 pickups list P0355 among many codes caused by a shorted engine harness.
What P0355 means
The engine computer found an electrical problem in the circuit that fires ignition coil E. Scanners call it Ignition Coil E Primary/Secondary Circuit. The computer switches each coil on and off to make the spark, and on many engines the coil sends a confirmation signal back. When the current, voltage or feedback on coil E’s circuit isn’t what the computer expects, it sets P0355.
On engines with one coil per spark plug, coil E is the coil for cylinder 5, so this code belongs to five-, six- and eight-cylinder engines. On a V6 or V8, cylinder 5 can sit on either bank depending on the maker’s numbering; the service information or the diagram on the engine cover shows which.
This is a circuit code, not a misfire count. The coil itself, its connector, its wiring, its power and ground, or the computer that drives it can all set it.
Is it safe to drive?
Short trips only, and stop if the light starts flashing. When coil E drops out, cylinder 5 usually misfires, and you feel a shake at idle or a stumble under load. With a steady light and mild roughness, drive gently to a shop and avoid towing or hard acceleration. A flashing check engine light means the misfire is heavy enough to overheat the catalytic converter; pull over and have the car towed. The same goes for a stall, a no-start, or several blown fuses at once.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Loose, corroded or wet coil connector, or chafed wiring | Look at coil E’s plug for corrosion, water, a broken lock tab or a pinched wire; wiggle the harness with the engine running | $100–$250 |
| Failed ignition coil E | Swap coil E with a neighbor on the same bank; the code changes to that coil’s number | $120–$300 for one coil |
| Poor engine ground or coil power feed | Voltage-drop test on grounds and the coil supply; often several P035X codes at once | $100–$250 |
| Software fault | Shop finds a matching bulletin for your engine | $100–$200; often $0 under a bulletin |
| Engine computer coil driver failed | Wiring and coil test good, but the computer’s output for coil E is dead | $800–$1,800 plus programming |
What to check first
- Read all the codes. P0355 alone points to coil E’s own circuit. P0355 with P0356 points to a shared harness branch; a long list of unrelated codes points to a harness short.
- Inspect coil E’s connector. Unplug it, look for water, corrosion or pushed-back pins, and check that nothing presses on the harness.
- Swap the coil with a neighbor, clear the code and drive. If the code follows the coil, replace the coil.
- Check power and ground at the coil with a meter or test light, including the engine-to-body ground straps and fuses.
- Suspect the computer last, only after the wiring checks out end to end.
The bulletins point at wiring more than coils. Ford’s bulletin for 2014–2016 F-250 and F-350 trucks with the 6.2L engine describes an open circuit in the coil connectors for cylinders 5 and 6 caused by rubbing on the intake air resonator. GM’s notices for 2019–2021 Silverado and Sierra 1500 pickups tell dealers to inspect the engine harness for a short when P0355 shows up with no-start, blown fuses and many other codes. Ford also notes that some 2021–2024 Broncos and 2023–2025 gas Super Duty, E-Series and medium-duty trucks can log coil codes against the wrong cylinder until the computer is updated.
Only 7 complaints filed with NHTSA mention P0355, too few to show a pattern by model.
What it costs
The cheap outcome is a connector, ground or wiring repair, $100–$250. The common outcome is one ignition coil, $120–$300. The expensive outcome is an engine computer, $800–$1,800 plus programming, which is rare and should only follow a full circuit test. An hour of diagnosis, usually $100–$180, is cheaper than buying a coil for a pinched wire. If you want to talk through your codes first, ask our AI mechanic.
Related codes
P0355 often comes with P0305, the cylinder 5 misfire it causes, or with P0300. If P0351 through P0354 are also set, look at the shared power and ground first. For what a steady light means in general, see check engine light on and can I drive with the check engine light on.
What owners report to NHTSA
7 complaints filed with NHTSA mention P0355, 5 of them since 2015, across 5 different models. The component owners most often filed it under: electrical system.
Manufacturer service bulletins that name P0355
19 technical service bulletins and manufacturer communications filed with NHTSA mention P0355, from 6 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- FORD F-450 SD (2023, 2024, 2025), bulletin 10254127: Some 2023-2024 F-Super Duty/F-53 Motorhome/F-59 Commercial Stripped Chassis or 2023-2025 E-Series/F-650/F-750 vehicles equipped with a gas engine may exhibit an illuminated MIL with ignition system DTC(s) P0352, P0353, P…
- FORD BRONCO (2021, 2022, 2023, 2024), bulletin 10251954: Some 2022-2024 Broncos Raptors built on and before 13-Feb-2024 and 2021-2024 Broncos equipped with a 2.3L EcoBoost engine may exhibit an illuminated MIL with ignition system DTC(s) P0352, P0353, P0354, P0355, P0357, P230…
- CHEVROLET SILVERADO 1500 (2019, 2020, 2021), bulletin 10193465: This Preliminary information communicates the following issues and directs dealership to inspect the engine harness for shorting. Some customers may comment on any of the following concerns: - SES MIL - No Start - No Cra…
- GMC SIERRA 1500 (2019, 2020, 2021), bulletin 10193465: This Preliminary information communicates the following issues and directs dealership to inspect the engine harness for shorting. Some customers may comment on any of the following concerns: - SES MIL - No Start - No Cra…
- FORD F SUPER DUTY, bulletin 10136577: Some 2014-2016 F-250 and F-350 vehicles equipped with a 6.2L engine may exhibit an illuminated MIL with DTC P0355 and/or P0356. This may be due to an open circuit in the coil-on-plug connectors for cylinders 5 and/or 6 d…
- BUICK ENCLAVE (2009), bulletin 10113025: This Preliminary Information communication provides information to the technician about vehicles that have a Service Engine Soon Malfunction Indicator Lamp on. Technician will find Diagnostic Trouble Codes P0300, P0301, …
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
Can a four-cylinder engine set P0355?
On a normal four-cylinder with one coil per plug, no: there is no coil E. P0355 shows up on five-, six- and eight-cylinder engines. If a four-cylinder reports it, recheck the vehicle selection on the scanner.
Is P0355 the same as a cylinder 5 misfire?
Not quite. P0355 means the computer found an electrical fault in coil E's circuit. That usually causes a misfire on the cylinder it fires, so P0305 often shows up with it, but P0355 tells you to look at the coil circuit first.
Will a new coil fix P0355?
Only if the coil is the problem. Swap coil E with a neighbor on the same bank first. If the code moves to that neighbor's code, the coil is bad. If P0355 stays, the fault is in the wiring, connector, ground or computer.
Why do I have P0355 and P0356 together?
Two coils rarely fail on the same day. Look at what they share: a harness branch, a connector that got pinched, or a ground. On some Ford 6.2L trucks a bulletin covers exactly that pair.