P036A: Ignition G Control Signal Circuit/Open

Ignition G is one of the control signal lines from the engine module to an ignition module, ignition output stage or group of coils; which cylinders it serves is defined by the manufacturer, not by the code standard. The code concerns the logic-level control signal, not the coil's primary current (that has its own codes, P0351 ff and P2300 ff). P036A means the control line is open – the module sees a voltage with its driver off that indicates high resistance. No manufacturer using these codes was found – neither GM nor Ford use the Ignition E to H codes; GM reports coil control faults as P0351 ff (open above 30 kΩ) – so the description follows CARB and that analogy. The affected coils fire wrongly or not at all, causing misfire; many modules then shut off injection to those cylinders to protect the catalyst.

Symptoms

• Check engine light on
• Misfire, jerking, rough idle
• Loss of power, possibly cylinders shut off
• Additional misfire codes P0300 ff

Most likely causes

• Control line or connector pin open (corrosion, pushed-back pin)
• Ignition module or coil with integrated driver of this group faulty
• Supply or ground of the ignition module faulty
• Driver stage in the engine module

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and wiring of the coil indicated
2. Check the continuity of the wire between the component and the control module.
3. Check the condition of the spark plug
4. Swap the coil with another cylinder and see if the code changes
5. Measure the power supply and control signal using the manufacturer's wiring diagram

Good to know

• Repair difficulty: medium
• It can trigger limp mode.
• It affects emissions.

What each character of P036A means

• P: Powertrain: engine and transmission
• 0: Generic code: same on every make
• 3: Ignition and misfires
• 6A: Specific fault in that system

Frequently asked questions

Can I keep driving with code P036A?

Drive as little as possible. If you feel jerking or the light flashes, stop: a misfire can damage the catalytic converter.

What causes code P036A?

The most common causes are: control line or connector pin open (corrosion, pushed-back pin); ignition module or coil with integrated driver of this group faulty; supply or ground of the ignition module faulty.

Related codes

• P036BIgnition G Control Signal Circuit Low
• P036CIgnition G Control Signal Circuit High
• P0300Random/Multiple Cylinder Misfire Detected
• P0351Ignition Coil A Primary Control Circuit/Open
• P2300Ignition Coil A Primary Control Circuit Low

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 18OBDG03A Engine Diagnostics
• newtonnet.co.uk: fordobd2012

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.