Worn or failing ignition coil D (internal secondary winding fault); Worn, fouled or incorrectly gapped spark plug on the cylinder served by coil D; Damaged, cracked or poorly seated coil boot or plug lead (where fitted), allowing voltage leakage; Wiring or connector fault at coil D, such as corrosion, loose pins or chafed wires; Poor power or earth supply to the coil circuit; Fault within the engine control unit's coil driver.

P1363

Ignition Coil D Secondary Circuit Malfunction.

Mercury
Powertrain
Manufacturer code
Medium severity

How this code is built

P: SystemPowertrain
1: Defined byThe manufacturer
3: AreaIgnition system or misfire
63: FaultThe specific fault in that area

What it means

P1363 on a Mercury means the engine control unit has detected a fault in the secondary circuit of ignition coil D. The control unit monitors the ignition signal and coil behaviour, and it set the code when the secondary side did not behave as expected. Which cylinder coil D serves depends on the model and engine, so confirm this from the workshop data for the vehicle.

Symptoms

Engine misfire or rough running, especially at idle
Hesitation or loss of power under acceleration
Flashing or constant engine warning light
Poor fuel economy
Hard starting or intermittent stalling
Fuel smell or raw fuel in the exhaust

Possible causes

Worn or failing ignition coil D (internal secondary winding fault)likely
Worn, fouled or incorrectly gapped spark plug on the cylinder served by coil Dlikely
Damaged, cracked or poorly seated coil boot or plug lead (where fitted), allowing voltage leakagepossible
Wiring or connector fault at coil D, such as corrosion, loose pins or chafed wirespossible
Poor power or earth supply to the coil circuitpossible
Fault within the engine control unit's coil driverrare

How to diagnose

Read all stored and pending codes and the freeze frame data to see engine load, speed and temperature when the fault set. Check for any misfire codes alongside it.
Confirm from the workshop data for the specific model and engine which cylinder coil D serves.
Visually inspect coil D, its boot or lead, and the connector for cracks, carbon tracking, oil contamination, moisture and damage.
Remove and inspect the spark plug for that cylinder, checking wear, deposits and gap against the specification.
Check the coil connector and wiring for corrosion, bent or loose pins and damaged insulation, and carry out a wiggle test with the engine running.
Check the coil's power supply and earth with a multimeter, and test the coil resistance against the manufacturer's specification.
Swap coil D with a coil from another cylinder, clear the codes and see whether the fault follows the coil.
Use an oscilloscope to check the coil's ignition waveform if the fault is still unresolved.

How to fix

Replace ignition coil D if it fails testing or the fault follows it when swapped.
Replace the spark plugs, preferably as a set, with the correct specification and gap.
Replace damaged coil boots or plug leads.
Repair or replace damaged wiring, and clean or renew corroded connector terminals.
Repair any power or earth supply fault in the coil circuit.
Only after all other causes are ruled out, diagnose the control unit's coil driver and replace or repair it if confirmed faulty.

Can I keep driving?

Medium severity

Light driving to a workshop is usually acceptable, but avoid heavy loads and high revs. If the engine warning light flashes, indicating an active misfire, stop driving and get it checked, as unburnt fuel can overheat and damage the catalytic converter.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.