What does it mean?
P1351 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: ICM Ignition Control Circuit High Input .
Symptoms
- Engine will not start, or starts and immediately stalls
- Sudden cut-out while driving with no warning
- Rough running and severe misfire when the engine does run
- Check engine light on with ignition-related codes stored
- Tachometer reading unstable or dropping out during cranking
Likely causes
- Open ignition control wire between the control module and the ignition module
- Ignition module not switching the circuit because it has failed internally
- Loose, backed-out or corroded terminals in either module connector
- Poor ground at the ignition module, so the circuit never pulls down properly
- Ignition control wire shorted to a battery-voltage circuit in a damaged harness section
- Faulty crank position or pickup signal, leaving the ignition module without a trigger
- Failed ignition control output inside the powertrain control module
How to fix it
- Verify spark output during cranking to confirm the ignition side is genuinely inoperative
- Inspect both module connectors for corrosion, backed-out terminals and evidence of overheating
- Measure the ignition control circuit voltage with the key on and again during cranking to see whether it ever pulls low
- Test the circuit for continuity end to end and for a short to battery voltage
- Check the ignition module ground and mounting surface, cleaning corrosion and refitting with the correct thermal compound
- Confirm the crank or pickup signal reaching the ignition module is present and clean
- Replace the ignition module if the circuit tests good but it still does not switch, and evaluate the control module last