Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Circuit Description
The ignition control module (ICM) controls spark timing when the engine is cranking. During this Bypass mode of operation, the ICM triggers each ignition coil in the proper sequence at a pre-calibrated timing advance. The ICM is connected directly to the powertrain control module (PCM) and includes the following circuits:
- The medium resolution engine speed signal
- The camshaft position signal circuit
- A low reference circuit
- The low resolution engine speed signal circuit
- The ignition control (IC) timing control circuit
- The IC timing signal circuit
When the PCM begins receiving the 3X reference pulses from the ICM and the engine starts, the PCM applies 5 volts to the IC timing signal circuit. This allows the ICM to switch to the IC mode of operation and spark advance to be controlled by the PCM. The PCM monitors the IC timing signal circuit for errors. If the PCM detects a fault, DTC P1350 sets.
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.