Ignition Coil C Primary Control Circuit High

What it means

The engine computer found the voltage in the primary control circuit of ignition coil C higher than expected. This usually means the control wire is shorted to a voltage source, or the circuit or coil winding is open. On most engines with one coil per cylinder, coil C serves cylinder 3, and that cylinder may not fire.

Related codes: P2306P0353P0303P0300P2310

Symptoms4

• Engine shaking, usually with a misfire on cylinder 3.
• Hard starting or a noticeably rough idle.
• Check engine light on, possibly flashing during a severe misfire.
• Higher fuel consumption and a smell of unburned fuel from the exhaust.

Possible causes5

• Open circuit in the control wire or in the primary winding of coil C, which some computers report as high voltage.
• Coil C control wire shorted to the supply wire or another voltage source.
• Loose coil C connector or corroded terminals.
• Poor coil C ground on designs where the coil has a built-in driver.
• Driver circuit fault inside the engine computer (less common).

How to diagnose5

1. Find in the service information which cylinder coil C serves, and watch the cylinder 3 misfire counter.
2. Inspect the coil C connector and make sure the terminals are tight and free of corrosion.
3. Measure the primary resistance of coil C if possible and compare it with the manufacturer specification; infinite resistance means an open winding.
4. Unplug the connector and measure voltage on the control wire with the key on; unexpected voltage means a short to a voltage source. Also check wire continuity to the computer.
5. Swap coil C with the coil of cylinder 4; if the code changes to P2310, the coil is faulty.

How to fix5

1. Clean and reseat the connector, or replace it if the terminals are damaged.
2. Repair the open wire or the wire shorted to voltage in the coil C circuit.
3. Repair a poor ground point if the coil design relies on it.
4. Replace coil C if it has an internal open, and check the cylinder 3 spark plug.
5. Clear the codes, then road test and confirm neither the code nor the misfire returns.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a connector or wire repair, moderate when coil C is replaced, and reaches the upper end if the driver inside the engine computer is proven faulty, which is rare.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions