Faulty ignition coil C with an open or shorted primary winding; Damaged or corroded wiring or connector at ignition coil C; Open or shorted primary circuit wire between the PCM and ignition coil C; Failed PCM driver for the ignition coil C circuit; Poor ground connection for the ignition coil circuit; Spark plug or secondary ignition problem that stresses the primary circuit

DTC codes / Mazda codes / P1354

P1354 · MazdaIgnition Coil C Primary Circuit

Q: What does code P1354 mean?

Ignition Coil C Primary Circuit. P1354 on Mazda vehicles means the powertrain control module (PCM) has detected an abnormal condition in the primary circuit of ignition coil C, which is the low-voltage side that the PCM uses to trigger the coil. The PCM monitors the coil driver circuit for expected voltage and current behavior, and when the signal falls outside the programmed window it stores this code and may illuminate the check engine light.

P1354 on Mazda vehicles means the powertrain control module (PCM) has detected an abnormal condition in the primary circuit of ignition coil C, which is the low-voltage side that the PCM uses to trigger the coil. The PCM monitors the coil driver circuit for expected voltage and current behavior, and when the signal falls outside the programmed window it stores this code and may illuminate the check engine light.

SystemPowertrain

Code typeMazda specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Check engine light illuminated, often with no other symptoms besides the warning light
Engine misfire or rough running, especially under load or acceleration
Noticeable loss of power or hesitation during acceleration
Shaking or vibration at idle that may smooth out at higher RPM
Reduced fuel economy due to incomplete combustion in the affected cylinder
In some cases, a flashing check engine light if the misfire is severe enough to damage the catalytic converter

Common causes, most likely first

Faulty ignition coil C with an open or shorted primary winding
Damaged or corroded wiring or connector at ignition coil C
Open or shorted primary circuit wire between the PCM and ignition coil C
Failed PCM driver for the ignition coil C circuit
Poor ground connection for the ignition coil circuit
Spark plug or secondary ignition problem that stresses the primary circuit

How to diagnose and fix it

Scan all modules for stored and pending codes to confirm P1354 is current and not a ghost code from a past event
Inspect the ignition coil C connector and wiring for corrosion, chafing, or loose pins, and repair as needed
Measure the primary resistance of ignition coil C with a multimeter and compare it to the manufacturer specification
Check for battery voltage at the coil connector with the key on and verify the ground circuit integrity
Perform a wiggle test on the coil harness while monitoring coil primary voltage or misfire counters to reveal intermittent faults
Swap ignition coil C with a known-good coil from another cylinder and see if the code follows the coil or stays with the cylinder
If the circuit and coil test good, test the PCM driver output with an oscilloscope or a noid light and replace the PCM only if the driver is confirmed faulty

What Mazda coil C codes often hide

A loose or corroded ground strap on the engine block can cause a P1354 without any fault in the coil itself, because the PCM sees an abnormal voltage drop on the primary circuit.
Technicians sometimes replace the coil only to have the code return because the real problem is a chafed wire in the harness near the coil mounting bracket, which is a common wear point on several Mazda engines.
P1354 can be set by a failing spark plug or a cracked coil boot that forces the primary circuit to work harder, so always inspect the secondary side before condemning the coil.
On some Mazda models, a weak battery or charging system fault can trigger coil primary circuit codes because the PCM expects a stable supply voltage during the coil dwell period.
A misfire counter that stays at zero does not rule out P1354, since the PCM can detect a primary circuit fault before the misfire becomes severe enough to register.

Can I keep driving with P1354?

You can usually drive a short distance to a repair shop if the engine runs smoothly and the check engine light is steady, but avoid hard acceleration and heavy loads. If the light flashes or the engine misfires badly, stop driving to prevent catalytic converter damage.

Tools that help

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