Faulty ignition coil B itself, such as an open or shorted primary winding; Damaged or corroded wiring and connectors between the PCM and coil B; Failed PCM driver circuit for coil B (less common but possible); Poor ground connection for the coil or engine block; Aftermarket or incorrect coil installed that does not meet Ford specifications; Moisture intrusion into the coil connector or spark plug well causing corrosion

DTC codes / Ford codes / P1353

P1353 · FordIgnition Coil B Primary Circuit Fault

Q: What does code P1353 mean?

Ignition Coil B Primary Circuit Fault. P1353 on a Ford means the powertrain control module (PCM) has detected an electrical fault in the primary circuit of ignition coil B, which is the low-voltage side that the PCM uses to trigger the coil. The PCM monitors the coil driver circuit for abnormal voltage or current behavior and sets this code when the signal does not match expected values during engine operation.

P1353 on a Ford means the powertrain control module (PCM) has detected an electrical fault in the primary circuit of ignition coil B, which is the low-voltage side that the PCM uses to trigger the coil. The PCM monitors the coil driver circuit for abnormal voltage or current behavior and sets this code when the signal does not match expected values during engine operation.

SystemPowertrain

Code typeFord specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Often no symptoms besides the warning light, especially if the fault is intermittent
Engine misfire or rough running, particularly under load or acceleration
Noticeable loss of power and reduced fuel economy
Shaking or vibration from the engine bay that worsens with engine speed
In some cases, the engine may enter limp mode or flash the check engine light if misfiring is severe

Common causes, most likely first

Faulty ignition coil B itself, such as an open or shorted primary winding
Damaged or corroded wiring and connectors between the PCM and coil B
Failed PCM driver circuit for coil B (less common but possible)
Poor ground connection for the coil or engine block
Aftermarket or incorrect coil installed that does not meet Ford specifications
Moisture intrusion into the coil connector or spark plug well causing corrosion

How to diagnose and fix it

Inspect the coil B connector and wiring for corrosion, chafing, or loose pins, and repair as needed
Swap coil B with a known-good coil from another cylinder (if accessible) to see if the code moves, confirming a coil fault
Measure the primary resistance of coil B with a multimeter and compare to Ford specifications
Check for battery voltage at the coil B connector with the key on, and check the ground circuit for continuity
Perform a wiggle test on the harness while monitoring coil B data to catch intermittent wiring faults
If wiring and coil check out, test the PCM driver circuit with a noid light or oscilloscope to verify the trigger signal
Replace the faulty coil or repair the PCM driver as needed, then clear the code and verify the repair with a road test

What Ford technicians check before replacing coil B

A P1353 can be set by a faulty spark plug or spark plug boot that causes the coil to fire erratically, so always inspect the secondary ignition components first.
On many Ford engines, coil B is not necessarily the second coil in firing order; always consult the specific engine's coil identification diagram to avoid replacing the wrong coil.
Intermittent P1353 codes often trace back to a chafed wire in the harness near the coil mounting bracket, which is easy to miss during a visual inspection.
A weak battery or charging system fault can cause low voltage at the coil primary circuit and trigger this code, so verify battery and alternator health before condemning the coil.
Aftermarket coils with incorrect primary resistance are a common cause of repeat P1353 codes, and using an OEM-quality replacement is critical for a lasting repair.

Can I keep driving with P1353?

You can usually drive with P1353 if the engine runs smoothly, but avoid heavy acceleration or towing until it is repaired. If the check engine light flashes or the engine misfires severely, stop driving to prevent damage to the catalytic converter.

Tools that help

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Guidance is general and written for Ford vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.