Ignition Coil E Primary/Secondary Circuit Malfunction
The P0355 code indicates a malfunction in the primary or secondary circuit of ignition coil E. This coil is responsible for providing spark to cylinder 5 (or the specific cylinder designated as 'E' by the manufacturer). The Powertrain Control Module (PCM) monitors the voltage and current in the coil's primary circuit; if it detects an open, short, or excessive resistance, it sets this code. A faulty coil, damaged wiring, or a poor electrical connection are common causes.
01. Most Common Causes
- Faulty ignition coil E
- Open or shorted wiring in the coil circuit
- Poor electrical connection at the coil connector
- Failed PCM (rare)
02. Symptoms You Will Notice
- Engine misfire on cylinder 5
- Check Engine Light illuminated
- Rough idle or hesitation during acceleration
- Decreased fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0355 is present. Check for additional misfire codes.
Step 2: Inspect ignition coil E connector for corrosion, damage, or loose pins. Clean or repair as needed.
Step 3: Measure resistance of coil E primary circuit (typically 0.5-2.0 ohms) and secondary circuit (typically 6-10 kohms). Replace if out of spec.
Step 4: Swap coil E with another cylinder. If the code follows, replace the coil. If not, check wiring and PCM.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as the misfire can damage the catalytic converter and cause poor performance. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
Replacing an ignition coil typically costs $50-$150 for parts and labor, depending on vehicle make and model.