Quick answer: The P0355 code indicates a circuit malfunction in ignition coil E, which directly controls spark delivery to cylinder 5. It affects your engine’s ignition system, causing severe engine misfires and rough performance. This issue requires prompt repair to prevent unburnt fuel from destroying your catalytic converter.
Seeing a check engine light alongside code P0355 can be alarming, especially when your engine starts shaking or losing power. This diagnostic trouble code points specifically to an issue in the control circuit for ignition coil E, usually cylinder 5. In this article, you will learn what triggers this code, how to troubleshoot it safely, and what fixes are required to get your vehicle running smoothly again.
What Does P0355 Mean?
Modern engines use a Coil-on-Plug (COP) system where individual ignition coils sit directly on top of each spark plug. Ignition coil “E” represents the fifth coil channel in the ignition sequence, which corresponds to cylinder 5 on most engines. The Powertrain Control Module (PCM) constantly monitors the voltage and resistance of the control signals sent to each coil. When the PCM detects an abnormal voltage spike, open circuit, or short circuit in the primary or secondary control loop of coil E, it sets code P0355 and triggers the check engine light.
Symptoms
- Illuminated or flashing Check Engine Light
- Severe engine misfires, shaking, or rough idling
- Noticeable loss of power during acceleration
- Increased fuel consumption
- Strong smell of raw gasoline from the exhaust pipe
- Engine hesitation or stalling when stopping
Possible Causes
Replacing the ignition coil right away is a common mistake; always inspect the wiring and connector first to avoid replacing a perfectly good part.
- Loose, cracked, or corroded wiring connector at ignition coil E
- Frayed, melted, or shorted harness wires between the coil and the PCM
- Faulty ignition coil E (cylinder 5 coil)
- Fouled or worn out spark plug causing excess resistance on cylinder 5
- Faulty Powertrain Control Module (PCM) or driver circuit failure
Check These Yourself Before Visiting a Mechanic
- Inspect the Connector: Locate ignition coil E on cylinder 5. Press the plastic release tab, disconnect the plug, and look for bent pins, moisture, or green corrosion inside the housing.
- Perform a Coil Swap: Swap ignition coil E with coil A or B. Clear the codes with a scanner and restart the engine. If the code changes to P0351 or P0352, the coil itself is bad. If P0355 remains, the problem lies in the wiring or control circuit.
- Check for Wiring Damage: Inspect the short wire lead running from the coil harness for chafing against heat shields or damage from rodents.
How to Fix It
- Perform a thorough visual inspection of cylinder 5 coil wiring, terminal pins, and locking clips.
- Swap the ignition coil to another cylinder to confirm whether the failure follows the coil or stays on the circuit.
- Test for 12 volts of power and ground at the coil harness plug using a digital multimeter.
- Inspect and replace the spark plug on cylinder 5 if it exhibits severe carbon buildup or oil fouling.
- Repair damaged wire harnesses or replace the faulty ignition coil if circuit tests fail.
- Verify PCM driver signal outputs if new hardware fails to generate spark.
Estimated Repair Costs (2026)
| Job | Parts ($) | Labor ($) |
|---|---|---|
| Ignition Coil E Replacement | $40 – $120 | $50 – $100 |
| Spark Plug Replacement (Cylinder 5) | $15 – $40 | $40 – $80 |
| Wiring Harness Repair | $20 – $50 | $100 – $200 |
| PCM Replacement & Programming | $400 – $900 | $150 – $300 |
Note: These are 2026 estimates in US dollars; actual repair costs will vary depending on vehicle make, model, and local shop labor rates.
Frequently Asked Questions
Can I drive with the P0355 code?
No, driving with code P0355 is not recommended. A circuit malfunction causes cylinder 5 to misfire continuously, dumping unburnt fuel directly into your exhaust system. This can overheat and permanently ruin your catalytic converter within a short distance.
How do I clear the P0355 code?
You can clear P0355 by connecting an OBD-II scanner to your car’s diagnostic port and selecting the clear codes function. However, if you do not fix the underlying electrical fault or coil failure, the code will trigger again almost instantly when you turn on the ignition.
Which cylinder corresponds to Coil E?
In standard OBD-II diagnostic protocol, Coil E refers to cylinder 5. You should check your vehicle manufacturer’s engine diagram to pinpoint the exact physical location of cylinder 5 on your engine block, as cylinder numbering varies between inline and V-shaped engines.