Wiring fault in the coil G control circuit, such as a short to voltage or chafed insulation touching a live wire; Faulty ignition coil G, or a failed driver built into the coil; Corroded, loose or damaged connector terminals at the coil or control unit; Open circuit in the control wire or a poor earth or power supply to the coil, causing the signal to float high; Separate ignition driver module fault, on engines that use one; Fault in the engine control unit output driver.

P036C

Ignition G Control Signal Circuit High.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
3: AreaIgnition system or misfire
6C: FaultThe specific fault in that area

What it means

P036C means the engine control unit has detected that the control signal circuit for ignition coil or driver 'G' is reading higher than expected. The control unit monitors the trigger signal it sends to the coil or its built-in driver, and it set the code when the voltage stayed high when it should have been switching or low. Which cylinder 'G' refers to depends on the engine, so check the manufacturer's information for the model.

Symptoms

Engine warning light on
Misfire or rough running, particularly at idle or under load
Hesitation or loss of power
Hard starting or an occasional no-start
Poor fuel economy
Flashing warning light under load if a severe misfire develops

Possible causes

Wiring fault in the coil G control circuit, such as a short to voltage or chafed insulation touching a live wirelikely
Faulty ignition coil G, or a failed driver built into the coillikely
Corroded, loose or damaged connector terminals at the coil or control unitpossible
Open circuit in the control wire or a poor earth or power supply to the coil, causing the signal to float highpossible
Separate ignition driver module fault, on engines that use onerare
Fault in the engine control unit output driverrare

How to diagnose

Read all stored and pending codes and the freeze frame data. Note engine load, speed and temperature when the fault set, and check for other misfire or coil codes.
Confirm from the manufacturer's information which cylinder and coil 'G' is on this engine, and check for any relevant technical bulletins.
Inspect the coil G connector and wiring for damage, heat, chafing, water ingress, corrosion and pushed-back or loose terminals.
Check the coil's power supply and earth connections against the wiring diagram.
Swap coil G with a known good coil, clear the code and see whether the fault follows the coil.
With the ignition off and the control unit connector disconnected where the manufacturer's procedure allows, test the control wire for continuity and for shorts to voltage or earth.
Use an oscilloscope or the manufacturer's procedure to check the control signal at the coil connector while cranking or running.
If the wiring, supply and coil all test good, consider a fault in the driver module or control unit, and confirm the diagnosis before replacing anything.

How to fix

Repair or replace damaged wiring in the coil G control circuit, and secure it clear of heat and rubbing points.
Clean or repair the connector terminals, or replace the connector if it is corroded or damaged.
Replace ignition coil G if it is faulty. Inspect the spark plug for that cylinder and replace it if it is worn or fouled.
Restore a good power supply or earth to the coil circuit.
Replace the ignition driver module or repair or replace the control unit only once it is confirmed faulty, following the manufacturer's procedure.

Can I keep driving?

Medium severity

Short, gentle journeys are possible, but avoid heavy loads and high revs because misfires can damage the catalytic converter. If the warning light flashes or the engine runs very roughly, stop driving and get it recovered.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.