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P2307 — Ignition Coil C Primary Control Circuit High

Manufacturer-specificPowertrain (engine & transmission)

P2307 indicates that the powertrain control module (PCM) has detected an abnormally high voltage condition in the primary control circuit for ignition coil C, which typically corresponds to the cylinder 3 coil. This high voltage reading usually results from a short to voltage in the wiring, an open circuit, or a fault within the coil itself that prevents the PCM from properly grounding the circuit. The condition disrupts the ignition firing sequence for that cylinder, resulting in a misfire.

Symptoms

What causes it — most likely first

1. Short to voltage in the ignition coil control circuit

The low-voltage control wire running between the PCM and coil C may have chafed through its insulation and contacted a battery voltage source, holding the circuit high when the PCM attempts to ground it.

2. Open circuit in the ignition coil primary control circuit

A break in the control wire or a disconnected connector creates an open circuit, which the PCM may interpret as a high voltage condition due to lack of continuity.

3. Faulty ignition coil C

Internal damage to the coil's primary winding, such as an open circuit or short, can cause abnormal voltage feedback that the PCM detects as a circuit high condition.

4. Corroded or damaged connector terminals

Moisture intrusion or oxidation at the coil or PCM electrical connector can create high resistance or intermittent contact that mimics a high-voltage fault in the circuit.

5. PCM driver circuit failure

Although uncommon, the internal transistor inside the PCM that grounds the ignition coil primary circuit may fail in a way that prevents voltage pull-down, setting a high circuit code.

How it's diagnosed

  1. Visually inspect the wiring harness between the PCM and coil C for chafing, melting, or rodent damage that could cause a short to voltage.
  2. Disconnect coil C and measure the primary resistance across its terminals, comparing the value to manufacturer specifications to identify internal coil faults.
  3. With the ignition on, use a multimeter to check for battery voltage on the control circuit at the coil connector; voltage present when the circuit should be grounded indicates a short to power.
  4. Perform a continuity test between the coil C control circuit pin and the corresponding PCM pin to verify the wire is not open, and check for continuity to power sources to confirm no short exists.
  5. Swap ignition coil C with a coil from a different cylinder; if the misfire moves or the code changes to the new cylinder location, the coil is faulty.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationManufacturer-specific (P1/B1/C1/U1)
Related codesP2300 — Ignition Coil Primary Control Circuit P2301 — Ignition Coil Primary Control Circuit P2302 — Ignition Coil Secondary CircuitP2303 — Ignition Coil B Primary Control CircuiP2304 — Ignition Coil B Primary Control CircuiP2305 — Ignition Coil B Secondary Circuit

Frequently asked

Is it safe to drive with a P2307 code?

Limited driving is possible, but prolonged operation is not recommended because unburned fuel from the misfiring cylinder can overheat and permanently damage the catalytic converter.

Does this code always mean the ignition coil needs to be replaced?

No, while a defective coil is a possible cause, wiring issues such as shorts to voltage or open circuits are frequent culprits and should be ruled out before replacing parts.

Should I replace the PCM (engine computer) to fix this code?

PCM replacement is rarely the solution for P2307; the code almost always stems from wiring or coil issues. Only consider the PCM after thoroughly verifying the integrity of the harness and coil.

Which specific cylinder is 'Ignition Coil C'?

Typically cylinder 3, but the lettering convention varies by manufacturer and engine design; consult the service manual for your specific vehicle to confirm the exact cylinder.