P0354: Ignition coil D primary or secondary circuit fault

Most likely causes

What to test first

Start at step 1. Each result tells you what it means and where to go next.

1. 1

   Step 1: With the engine off, find which coil is D in the service information, then inspect it and its connector: look for cracks, carbon tracks, a loose or corroded connector, and oil or water in the plug well.

   Low riskTool: flashlight, service information for which coil is B

   • IfOil or water in the well, or a worn plug

     It meansFix the leak and plug as well as the coil.

     Points to: Worn spark plug or oil/water in the plug well damaging the coil

   • IfCracked, burned or tracked coil

     It meansThe coil is damaged.

     Points to: Failed ignition coil D

   • IfEverything looks good

     It meansCheck the grounds and supply.

     Go to step 2

2. 2

   Step 2: With the engine off, check that the engine and cylinder head ground straps near the coils are clean and tight, and look up any bulletin for your vehicle.

   Low riskTool: hand tools, service information

   • IfA ground is loose or corroded

     It meansClean and tighten it to specification, clear the code and retest.

     Points to: Poor engine ground connection (2017 Escape 1.5L)

   • IfGrounds are good

     It meansCheck the coil supply.

     Go to step 3

3. 3

   Step 3: Unplug the coil and, with the ignition on and the engine off, check for supply voltage at the harness connector.

   Use cautionTool: digital multimeter or test lamp, wiring diagram

   Warning:Keep the engine off. Do not crank the engine with a coil unplugged or probe the coil while the engine runs; ignition voltage can cause a serious shock.

   • IfSupply is low or missing

     It meansA wiring, fuse or relay problem.

     Points to: Coil supply, ground or control wiring or connector fault

   • IfSupply is normal

     It meansCheck the coil itself.

     Go to step 4

4. 4

   Step 4: With the engine off, swap coil D with a coil from another cylinder (where they are interchangeable), clear the code and see whether the fault moves.

   Use cautionTool: hand tools, scan tool

   Warning:Only swap coils with the engine off and cool. Keep clear of moving parts when restarting.

   • IfThe code moves to the other coil's letter

     It meansThe coil has failed.

     Points to: Failed ignition coil D

   • IfThe code stays on coil D

     It meansThe fault is in the wiring, computer or software.

     Go to step 5

5. 5

   Step 5: Have a shop check the coil control and low-reference circuits from the engine computer, and look for bulletins or software updates for your vehicle.

   Best left to a shopTool: scan tool with output controls, lab scope, service information

   Warning:Checks with the engine running involve high ignition voltage and moving parts. Leave this to a shop.

   • IfControl or low-reference wire open, shorted or high resistance

     It meansRepair the wiring.

     Points to: Coil supply, ground or control wiring or connector fault

   • IfA bulletin or update covers the code

     It meansFollow the bulletin.

     Points to: Engine computer software (some models)

   • IfThe code names a cylinder that tests fine on a listed Ford

     It meansFord says the code can name the wrong cylinder; find the real one with a power balance test.

     Points to: Failed ignition coil D

Symptoms

• Rough running or misfire
• Reduced power
• Hard starting or no start Gets more serious: stop and have it checked.
• Engine stalls while driving Gets more serious: stop and have it checked.
• Check engine light flashing Gets more serious: stop and have it checked.

Compare with: Rough idle with the check engine light on, Car shaking with the check engine light on

How to fix

1. 1

   Step 1: Write down every stored code and the freeze-frame data before clearing anything, so you can tell whether the code comes back.

2. 2

   Step 2: If the plugs are due by the maintenance schedule, have them replaced along with any failed coil.

   Warning:Only remove coils and plugs with the engine off and cool, and tighten plugs to the specified torque.

On your vehicle

Related codes

• P0353Ignition coil C primary or secondary circuit fault

  Same system Supported by vehicle data

  P0353 is the same fault on ignition coil C. Several coil codes at once point to a shared supply, ground or software cause rather than separate coil failures.

• P0352Ignition coil B primary or secondary circuit fault

  Same system Supported by vehicle data

  P0352 is the same fault on ignition coil B. Ford and Toyota bulletins list P0351-P0354 together, so check shared grounds, supply and software when more than one coil code is stored.

• P0300Random or multiple-cylinder misfire detected

  Shares causes Common general cause

  A failed coil causes misfire, so P0300 or a cylinder misfire code often sets alongside P0354. Fix the coil circuit first.

• P0420Catalytic converter efficiency below the computer's limit (Bank 1)

  Primary / secondary Common general cause

  Likely primary: P0354. Unburned fuel from a coil misfire can overheat the catalytic converter, which can later set P0420. Fix the coil promptly.

All Ignition and engine position sensors codes