P0354
Fix within a few daysThe engine computer detected a problem with the ignition coil circuit for cylinder #4.
Code P0354 means the engine computer detected a problem with cylinder #4's ignition coil circuit. Common causes: Faulty ignition coil (70%), bad spark plug (15%), wiring issues (10%). Drivability: Limit driving, fix within a few days. Repair cost: $50-$100 DIY, $150-$500 professional.
Can I Drive With P0354?
Limit driving, fix within a few days
Essential trips under 10 miles, avoid highways and heavy acceleration.
Stop driving immediately if: Flashing Check Engine Light, significant power loss, loud engine noises, burning smell.
Symptoms of P0354
- 1Check Engine Light is on or flashing
- 2Engine misfires or runs rough
- 3Reduced engine power
- 4Engine hesitation or stumbling during acceleration
- 5Rough idle
- 6Poor fuel economy
Common Causes of P0354
Parts most likely causing this code, ranked by probability
The ignition coil itself has failed internally, preventing proper spark to cylinder #4.
70% of P0354 cases are fixed by replacing this part
A worn, fouled, or damaged spark plug can cause the ignition coil to overwork or prevent proper combustion, triggering the coil circuit code.
15% of P0354 cases are are fixed by replacing this part
Damaged, corroded, or loose wiring or connector to the ignition coil can interrupt the primary or secondary circuit.
10% of P0354 cases are fixed by repairing this part
A faulty PCM/ECM is rare but can incorrectly interpret signals or fail to send proper commands to the ignition coil.
5% of P0354 cases are fixed by replacing this part
Check These First (Before Buying Parts)
- Visually inspect the ignition coil and its electrical connector for cylinder #4. Look for cracks, burn marks, or loose/corroded wires.
- Ensure the connector is fully seated on the coil.
How to Diagnose P0354
- 1Visually inspect the ignition coil and wiring for cylinder #4 for any obvious damage, corrosion, or loose connections.
- 2If possible, swap the ignition coil from cylinder #4 with a coil from a different cylinder (e.g., cylinder #1). Clear the code and drive the vehicle. If the code changes to P0351 (Ignition Coil 'A' Primary/Secondary Circuit Malfunction), the coil is faulty.
- 3Remove and inspect the spark plug for cylinder #4. Look for signs of wear, fouling, or damage. Replace if necessary.
- 4Using a multimeter, check for proper voltage and ground at the ignition coil connector for cylinder #4 with the key on.
- 5If the coil and spark plug are confirmed good, and wiring checks out, further diagnosis of the PCM may be necessary by a professional.
P0354 on Popular Vehicles
Ford F-150
2004-2014Ignition coil failures are very common, especially on 5.4L engines. Water intrusion into spark plug wells can damage coils.
80% fixed by coil/plug
Honda Accord
2003-2012Coil pack failures are a known issue. Inspect for oil leaks around the valve cover gasket that can foul spark plug wells and damage coils.
75% fixed by coil/plug
Chevrolet Silverado
2007-2013Ignition coils are a common failure point. Check for corrosion at the coil connector.
70% fixed by coil
Frequently Asked Questions
What does P0354 mean?
P0354 indicates the engine computer has detected a malfunction in the primary or secondary circuit of the ignition coil for cylinder #4. This means the coil is not firing correctly or the computer isn't seeing the correct signal from it.
Can I drive with P0354?
Limit driving, fix within a few days. Driving with a P0354 code means your engine is misfiring, which can quickly damage your catalytic converter due to unburned fuel entering the exhaust.
Will P0354 clear itself?
No, P0354 will not clear itself. The underlying issue with the ignition coil or its circuit must be repaired for the code to go away.
How do I fix P0354 myself?
Start by visually inspecting the coil and wiring for cylinder #4. The most common fix is replacing the ignition coil for cylinder #4. Consider replacing the spark plug for cylinder #4 at the same time.
How much does it cost to fix P0354?
DIY repair costs $50-$100 for a new ignition coil and spark plug. Professional repair costs $150-$500, including parts and labor.
P0354 keeps coming back - why?
If P0354 returns after replacing the coil, check the spark plug for cylinder #4. Also, thoroughly inspect the wiring harness and connector to the coil for damage or corrosion. A rare cause is a faulty PCM.
Will P0354 fail emissions/smog test?
Yes, P0354 will cause your vehicle to fail an emissions or smog test. A check engine light, especially one indicating a misfire, is an automatic failure.
What's the difference between P0354 and P0304?
P0354 specifically indicates a problem with the electrical circuit of the ignition coil for cylinder #4. P0304 indicates a misfire detected in cylinder #4, which can be caused by a faulty ignition coil, spark plug, fuel injector, or compression issue. P0354 is a more specific diagnosis of the ignition system.
P0354 on Ford F-150?
On Ford F-150s, especially 2004-2010 models with the 5.4L engine, ignition coil failures are very common. Often, water or oil can get into the spark plug wells, damaging the coil.
Questions to Ask Your Mechanic
Did you perform a coil swap test to confirm the coil is bad, or did you check the wiring to the coil for proper voltage and ground?
Good answer: Yes, I swapped the coil to cylinder #1 and the code followed it to P0351, confirming the coil is faulty. I also checked the spark plug and it looked good.
Repair Cost Estimate
DIY Repair
Parts only
$50-$100
Shop Repair
Parts + labor
$150-$500
Save $100-$400 by doing it yourself
Difficulty
intermediate
Time
0.5-1.5 hours
Intermediate - Replacing an ignition coil is simple, but diagnosing wiring issues or a faulty PCM requires a multimeter and more advanced diagnostic skills.
Cost of Waiting
Continued misfires send unburned fuel to your catalytic converter. This superheats and destroys the converter, turning a $50-$100 ignition coil job into a $1,200-$2,500 converter replacement.
While You're In There...
If one spark plug is worn, others are likely due. Replacing them with the coil prevents repeat labor and ensures optimal ignition.
Apply to the inside of the coil boot to prevent moisture intrusion and ensure a good electrical connection, extending coil life.
Tools You'll Need
- OBD-II Scan Tool
- Ratchet and socket set (for coil bolts)
- Spark plug socket (if replacing plug)
- Torque wrench (for spark plugs)
- Dielectric grease
- Multimeter (for advanced diagnostics)
P0354 is a common ignition system code. Most repairs involve replacing a single ignition coil, which is a straightforward fix that will get your engine running smoothly again.
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Your Next Steps
Step 1: Visually inspect the ignition coil and wiring for cylinder #4 for any obvious damage or loose connections.
Step 2: Perform a coil swap test. Move the cylinder #4 coil to another cylinder. If the code moves with the coil, replace the coil. If the code stays on cylinder #4, inspect the spark plug and wiring.
Step 3: Parts you'll likely need: One ignition coil for cylinder #4, and consider a new spark plug for cylinder #4. If your spark plugs are old, replace the full set.