What does it mean?
For the eighth ignition channel to fire its coil, the module must pull the control line down from its rest voltage. P036F is set when the module commands the channel but continues to read a high voltage, so no current flows through the coil driver input. The electrical picture is an open or high resistance path, or battery voltage being applied to the line from another circuit. Since the remaining ignition channels normally keep working, the shared supply and ground are rarely to blame; the fault sits in this channel's own wire, its terminals or the coil input it feeds.
Symptoms
- Steady misfire, rough idle and vibration felt in the cabin
- MIL on and flashing under load
- Reduced power, hesitation and dull throttle response
- Hard starting, particularly when cold or damp
- Popping from the exhaust and a smell of unburnt fuel
- Increased fuel consumption
Likely causes
- High resistance connection or a partial break in the H channel control wire
- Corroded, loose or spread terminals in the coil or module connector
- Control wire shorted to battery voltage through damaged insulation
- Open igniter input inside the eighth coil
- Poor ignition module ground, preventing the driver from pulling the line down
- Faulty module output stage, considered only after the wiring has been proven good
How to fix it
- Read the misfire counters and freeze frame data to pin down the cylinder and the conditions
- Inspect and probe the connector terminals at both ends of the circuit for tension and corrosion
- Measure the control line voltage with the ignition on and while cranking to confirm it stays high
- Perform continuity and voltage drop tests along the control wire
- Disconnect the module and test the line for a short to a permanently live circuit
- Check the coil supply, the ignition ground and the relevant fuse
- Repair the wiring or renew the coil, then clear the code and verify with a loaded road test