2754

What the Code Means

The DME continuously monitors the ignition coil primary circuit for shorts and opens. Code 2754 flags a fault on cylinder 3: either a short to battery positive or a missing impedance. In practice, that means the coil is internally shorted or open — the DME sees resistance in the primary circuit outside the allowed range and logs the failure.

Severity is moderate: the engine keeps running but with misfires, and you shouldn't put off the repair because of the risk to the catalytic converter.

Symptoms

• misfires on cylinder 3, the engine may run on three cylinders;
• stumbling under acceleration;
• hesitation when you stab the throttle;
• rough running, noticeable at idle.

Diagnosis and Repair

1. Read the codes with an INPA or ISTA scanner and confirm 2754 is present.
2. Swap the ignition coils from cylinder 3 and another cylinder (cylinder 4, for example).
3. Rescan: if the fault moved to the cylinder where you put the coil, the coil is bad and needs replacement. If the code stays on cylinder 3, look for the cause in the wiring or connector.
4. Install a new OEM coil: part number 12137594937 or equivalent.
5. Clear the codes and take a test drive to verify the fix.

Secondary Problems

• A bad coil causes misfires: unburned fuel reaches the catalytic converter and can destroy it — replacing the catalytic converter costs far more than replacing the coil.
• To protect the catalytic converter, the DME may shut off the injector on the faulty cylinder. The engine then runs even rougher, and emissions go up.