What Does P0355 Mean?
The ECM has detected a malfunction in the primary or secondary circuit of ignition coil E, which typically serves cylinder #5 on V6, V8, or inline-6 engines. The coil driver monitoring has identified that coil E is not functioning within normal operating parameters. This will cause a persistent misfire on cylinder 5, with associated rough running and power loss that is more noticeable on engines with fewer cylinders.
Common Causes
40%
Failed ignition coil E with internal winding failure, common on rear-bank coils due to reduced airflow and higher operating temperatures
25%
Damaged wiring or connector in the coil E circuit, especially on rear-bank cylinders where harness routing is tight and heat exposure is greater
20%
Worn or fouled spark plug on cylinder 5 causing excessive voltage demand
15%
ECM coil driver failure for the cylinder 5 ignition output
Diagnostic Steps
1
Swap coil E with an easily accessible coil from another cylinder. Clear codes and run the engine. If the code changes to the swapped cylinder's coil code, replace coil E.
2
Measure coil E primary resistance (0.4-1.0 ohms) and secondary resistance (6,000-12,000 ohms). On rear-bank coils, also check for carbon tracking on the coil tower.
3
Inspect the coil E connector and harness routing. On V-engines, the rear bank wiring is often routed near the firewall where heat soak and rodent damage are common.
4
Verify ECM driver signal at the coil E trigger wire during cranking. Confirm proper dwell timing and clean signal transitions.
5
Remove and inspect cylinder 5 spark plug for wear, fouling, and proper gap. On rear-bank cylinders, spark plugs are often overlooked during maintenance and may be significantly worn.
Estimated Repair Cost
$60 - $350
Parts + labor, varies by vehicle and location
The ECM has detected a malfunction in the primary or secondary circuit of ignition coil E, which typically serves cylinder #5 on V6, V8, or inline-6 engines. The coil driver monitoring has identified that coil E is not functioning within normal operating parameters. This will cause a persistent misf...
The most common cause of P0355 (Ignition Coil E Primary/Secondary Circuit Malfunction) is: Failed ignition coil E with internal winding failure, common on rear-bank coils due to reduced airflow and higher operating temperatures
Typical repair costs for P0355 range from $60 to $350, depending on the vehicle, location, and whether you do it yourself or go to a shop.
A dead cylinder 5 misfire reduces engine power output, especially noticeable under load. Continued driving with persistent misfire risks catalytic converter damage from unburned fuel reaching the exhaust.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0355 to identify the root cause.
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Quick Info
Category
Powertrain
System
Ignition System
Difficulty
Type
Generic (SAE)
Recommended Tools
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