What does code P0354 mean on a Mercedes-Benz and is it safe to drive?
P0354: Ignition Coil D Primary/Secondary Circuit Malfunction. Here's what it means on your Mercedes-Benz, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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What this code means
Fault in ignition coil D circuit (cylinder 4). This is the fourth coil in a coil-on-plug system. Diagnosis mirrors P0351–P0353 but targets cylinder 4.
Common causes for your Mercedes-Benz
- Failed ignition coil on cylinder 4
- Worn or fouled spark plug on cylinder 4
- Damaged coil wiring or connector
Symptoms
- Check Engine Light on or flashing
- Rough idle or misfire on cylinder 4
- Reduced performance
Typical fixes
- Replace ignition coil for cylinder 4
- Replace spark plug on cylinder 4
- Inspect coil connector and wiring
Repair cost range
For a Mercedes-Benz, repairs for P0354 often fall between $80 and $300, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.