Ignition and misfires code
P0354: Ignition coil D circuit problem
How this range is built
| Part of the job | Low | High |
|---|---|---|
| Parts | $30 | $120 |
| Labor: 0.4 to 1.2 hours × $125 to $175 an hour | $50 | $210 |
| Fees: shop supplies, disposal, diagnostics | $0 | $15 |
| Total, rounded | $80 | $350 |
The hourly rate is the BLS Occupational Employment and Wage Statistics, May 2025 average pay for this trade in Boston, $31.54 an hour, times 4 to 5.5 to cover what a shop bills (overhead, tools, insurance, profit). Parts are a band from budget aftermarket to the manufacturer part. Full method.
Not a repair shop, estimates only. Typical range, estimate. Not a quote. Your car, parts and shop change the number.
This is the range for the most common fix, ignition coil replacement (one coil). Which repair your car needs depends on a proper diagnosis.
The computer switches coil D on and off to fire a spark plug and checks the circuit for the right response. It found an electrical fault. Coil D is the fourth coil in the engine's arrangement, so that cylinder can misfire when accelerating or at idle until the problem is repaired.
- Safe to drive?
- Short trips only
- Most common cause
- Failed ignition coil
Steady light means gentle driving to a shop is okay. A flashing light means stop, since unburned fuel can damage the converter.
What you may notice
- Rough idle
- Misfire when accelerating
- Poor fuel economy
- Check-engine light
Common causes, most likely first
- Failed ignition coil
- Loose connector
- Worn spark plug
- Wiring damage
Check this first
Swap coil D with a neighbor, clear the code, and drive. If the code follows the coil, replace that coil. If the code stays in place, ask the shop to check the connector and wire, since a loose plug can fail like a coil.
Other repairs that sometimes fix P0354
| Repair | Typical range, Boston |
|---|---|
| Spark plug replacement | $95 to $580 |
| Diagnostic scan (check engine light) | $60 to $290 |
Before you pay
- Ask the shop what test showed this part is the cause, not just that the code appeared.
- Ask for parts and labor listed separately, and for the hours.
- Ask for a written OK before any extra work. Massachusetts rules require written authorization before repairs.
Got a quote already? Check it against the range. Want to see if your car has a recall tied to this problem? Check recalls by VIN.
Need to read a code yourself? OBD-II scanners on eBay (affiliate link, disclosure).
P0354 questions
What if it keeps coming back?
Then wiring or the engine computer may be involved. Ask for a circuit test between the coil and the computer before buying more coils, since a damaged wire can wreck new parts.
Does it need plugs too?
Often it is a good time to check them. A worn plug makes a coil work harder and can shorten its life, and if the plugs are already out of date, changing them with the coil saves labor.
Is it urgent?
If the light flashes, yes. A flashing light means a strong misfire that can overheat the catalytic converter. If the light is steady, drive gently and get it checked soon.
How much does it cost to fix P0354?
The most common fix, ignition coil replacement (one coil), has a typical range of $80 to $350 in Boston. It is an estimate built from parts prices and local labor wages, not a quote. Your car and shop change it.
Related codes
- P0353: Ignition coil C circuit problem
- P0355: Ignition coil E circuit problem
- P0304: Cylinder 4 misfire
More ignition and misfires codes
Code meaning written in our own words. Some codes mean different things on different makes, so check your scan tool or manual. Not a repair shop, estimates only.