Faulty ignition coil for cylinder 4 with an internal short to ground; Chafed or shorted IC control wire between the ECM and the cylinder 4 ignition coil; Corroded or loose connector pins at the ignition coil or ECM harness; Failed ECM driver for the cylinder 4 IC circuit; Aftermarket alarm or remote start wiring tapped into the IC circuit; Engine wiring harness damage from heat, rodents, or previous repairs

DTC codes / GM codes / P1354

P1354 · GMIC Output High Pulse Detected When Grounded Cyl 4

Q: What does code P1354 mean?

IC Output High Pulse Detected When Grounded Cyl 4. P1354 on a GM vehicle means the ignition control (IC) circuit for cylinder 4 is commanding a high output pulse while the circuit is grounded, which the engine control module (ECM) interprets as an abnormal short-to-ground condition. The ECM monitors the IC output line and expects it to behave as a controlled driver, so a continuous high signal when the line should be low indicates a wiring fault, a failed ignition coil, or an internal ECM driver problem.

P1354 on a GM vehicle means the ignition control (IC) circuit for cylinder 4 is commanding a high output pulse while the circuit is grounded, which the engine control module (ECM) interprets as an abnormal short-to-ground condition. The ECM monitors the IC output line and expects it to behave as a controlled driver, so a continuous high signal when the line should be low indicates a wiring fault, a failed ignition coil, or an internal ECM driver problem.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Engine misfire or rough running, especially noticeable at idle or under light load
Illuminated check engine light, often with a flashing light if the misfire is severe
Reduced engine power or hesitation during acceleration
Poor fuel economy and increased emissions
Often no symptoms besides the warning light if the fault is intermittent
Possible engine stall or hard starting in severe cases

Common causes, most likely first

Faulty ignition coil for cylinder 4 with an internal short to ground
Chafed or shorted IC control wire between the ECM and the cylinder 4 ignition coil
Corroded or loose connector pins at the ignition coil or ECM harness
Failed ECM driver for the cylinder 4 IC circuit
Aftermarket alarm or remote start wiring tapped into the IC circuit
Engine wiring harness damage from heat, rodents, or previous repairs

How to diagnose and fix it

Inspect the cylinder 4 ignition coil connector and ECM harness for corrosion, loose pins, or chafing
Disconnect the cylinder 4 ignition coil and check the IC control wire for continuity to ground with the key off
Swap the cylinder 4 ignition coil with a known-good coil from another cylinder and see if the code moves
Measure resistance of the IC control wire from the ECM connector to the coil connector to rule out an open or short
Check for aftermarket accessories tapped into the ignition wiring and remove or repair any improper connections
If wiring and coil test good, perform an ECM driver test with a scan tool or oscilloscope to confirm the ECM is commanding the fault
Replace the ECM only after all other causes are ruled out, and reprogram it to the vehicle

Why cylinder 4 IC codes mislead

A shorted ignition coil on cylinder 4 is the most common cause, but technicians often replace the ECM first because the code points to the IC output; always swap the coil before condemning the module.
The IC circuit is a low-current control line, so a cheap test light or incorrect probing can damage the ECM driver; use a high-impedance multimeter or oscilloscope for testing.
Aftermarket remote starters and alarm systems frequently splice into ignition control wires, creating intermittent shorts that set P1354 only under certain conditions.
A misfire from a bad spark plug or plug wire can cause the ECM to detect an abnormal IC pulse, so inspect secondary ignition components before chasing the control circuit.
On some GM engines, the IC circuit for cylinder 4 shares a ground path with other ignition coils, so a bad ground at one coil can set codes for multiple cylinders.

Can I keep driving with P1354?

You can drive the vehicle short distances to a repair shop if the check engine light is steady and the engine runs smoothly, but avoid heavy acceleration or towing. If the light is flashing 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 GM vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.