P0355

Universal

Ignition Coil E Primary/Secondary Circuit Malfunction

Definition source: General OBD-II reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Medium Severity

The engine computer detected an electrical problem in the primary or secondary circuit associated with ignition coil E. The coil helps create the spark that ignites the air-fuel mixture, and the computer monitors related circuit behavior. This code does not by itself prove the coil has failed. Depending on the cause, the engine may misfire, run poorly, or show no noticeable symptoms. The meaning of the coil designation and the correct test procedure depend on the vehicle, year, and engine.

Report an error with this code

⚠️ Before You Begin (Safety First)

If the engine is shaking badly, losing power, or the check-engine light is flashing, stop driving when it is safe to do so and arrange diagnosis; a severe misfire can damage the catalytic converter. Ignition systems can produce dangerous voltage. Do not touch ignition components while the engine is running or probe them without the correct vehicle-specific procedure.

Common Symptoms

  • The check-engine light may be on; it may flash if the fault is accompanied by a severe misfire.
  • The engine may idle roughly or misfire if the circuit problem interrupts spark delivery.
  • Acceleration may feel weak or uneven if the affected cylinder or cylinders do not ignite the mixture consistently.
  • Fuel consumption or exhaust emissions may increase if misfires occur.
  • There may be no obvious driving symptoms, especially if the fault is intermittent or detected before drivability changes.

Common Causes

  • An ignition coil or its internal primary or secondary circuit may be faulty.
  • A loose, corroded, or damaged coil connector may interrupt the electrical connection.
  • Wiring to the coil may be open, shorted, chafed, or damaged by heat or vibration.
  • A power supply or ground problem may affect the coil circuit.
  • A fault in the engine computer's coil-control circuitry is possible, but should be considered only after circuit and connection checks.

Diagnostic Steps

  1. Note whether the engine is misfiring, running roughly, or showing a flashing check-engine light. If symptoms are severe, stop driving when safe and arrange diagnosis.
  2. With the ignition off and the engine cool, visually inspect the ignition coil E connector and nearby wiring for looseness, corrosion, broken insulation, or heat damage. Do not touch or probe ignition components with the engine running.
  3. Check for related diagnostic codes and record available freeze-frame information before clearing codes; this can help show whether the fault occurred with a misfire or another electrical issue.
  4. If the connector is accessible and safe to handle, confirm it is seated and its locking tab is intact. Avoid forcing the connector or applying unapproved cleaners.
  5. If the code returns or wiring damage is visible, have the circuit tested using the service information for the exact vehicle, year, and engine. Do not replace the coil based on this code alone.

When to Call a Professional

A technician can review freeze-frame data and related codes, then inspect the coil E connector and wiring. Vehicle-specific electrical tests can help distinguish a coil fault from damaged wiring, a poor connection, a power or ground supply issue, or a control-module driver problem. The coil designation does not establish a cylinder number without vehicle-specific information.

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Commonly Asked Questions

Does P0355 mean ignition coil E must be replaced?

No. The code identifies a detected primary or secondary circuit malfunction, not a confirmed failed part. The coil, connector, wiring, power or ground supply, and control circuitry may need to be checked.

Does coil E identify a specific cylinder?

Not from this code alone. The cylinder or component represented by coil E depends on the vehicle's design and service information.

Can I keep driving with P0355?

That depends on symptoms. If the engine runs smoothly, prompt diagnosis is still advisable. Stop driving when safe if it is misfiring severely, losing power, or the check-engine light is flashing.

What helps distinguish a coil fault from a wiring fault?

A visual connector and wiring inspection, related-code and scan-data review, and vehicle-specific electrical tests can help identify whether the coil circuit, its connections, or the control side is responsible.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.