P2307 — Ignition Coil “C” Primary Control Circuit High #

Note: The description and wording of this code may change slightly depending on the vehicle manufacturer (OEM). Always refer to your vehicle’s specific service information.

• P2307 – Ignition Coil “C” Primary Control Circuit High (General, SAE standard)
• P2307 – Ignition Coil 3 Primary Circuit High (Ford, Chrysler, Toyota)
• P2307 – High Voltage on Coil “C” Primary (Honda, Nissan)
• P2307 – Primary Circuit High – Cylinder 3 (Hyundai, Kia)

Summary for code P2307 #

P2307 is an OBD-II trouble code indicating that the engine control module (ECM) has detected a high voltage condition in the primary control circuit of Ignition Coil “C”. The primary circuit is the low-voltage side of the coil, responsible for receiving signals from the ECM to trigger spark. This code points to an electrical problem—often a wiring fault, a faulty ignition coil, or problems with the ECM itself. It may cause drivability issues like rough running or misfire, but sometimes the only sign is the illuminated check engine light. Prompt diagnosis and repair are recommended to prevent damage to the catalytic converter or other engine components.

Common Symptoms for code P2307 #

The symptoms caused by P2307 can vary, depending on whether the fault is intermittent or persistent. Sometimes, the check engine light is the only warning. In other cases, noticeable performance issues appear. Typical symptoms include:

• Illuminated Check Engine Light (CEL)
• Noticeable engine misfire or hesitation, especially under load
• Rough idle or unstable RPMs
• Reduced engine power or acceleration
• Poor fuel economy
• Hard starting or extended cranking
• Possible increased exhaust emissions

Probable Causes for code P2307 (in order of likelihood) #

Several underlying issues can trigger a P2307 code. Some are more common than others, so it’s helpful to check them in order of probability:

1. Faulty ignition coil “C” itself (internal electrical fault or short)
2. Damaged, corroded, or loose wiring/connectors in the coil “C” primary circuit
3. Short to voltage in the coil “C” wiring harness
4. Faulty ECM/PCM (rare but possible, especially if other codes are present)
5. Aftermarket parts installed incorrectly (remote starters, alarms, etc.)

Step-by-step Diagnostic Guide for code P2307 #

Before replacing any parts, follow a systematic approach to avoid unnecessary repairs. Here’s how a professional technician would diagnose P2307:

• 1. Confirm the code: Use a scan tool to verify P2307 is active and check for related codes (especially misfire or coil codes).
• 2. Inspect ignition coil “C” and its wiring: Look for obvious signs of damage, corrosion, or loose connections at the coil and ECM.
• 3. Test coil “C” resistance: Using a digital multimeter, check the primary and secondary coil windings. Compare readings to OEM specifications.
• 4. Check for power and ground: With the ignition on, verify that coil “C” receives proper power and ground signals.
• 5. Wiggle test: Gently move harnesses while monitoring live data or the code status to detect intermittent wiring faults.
• 6. Swap test: If possible, exchange coil “C” with another cylinder’s coil. If the code moves, the coil is faulty; if not, wiring or ECM is likely at fault.
• 7. Check for short to voltage: Inspect the coil “C” control circuit for unwanted voltage (may require wiring diagram and advanced testing).
• 8. ECM/PCM diagnosis: Only after ruling out all other causes, consider ECM failure. This is rare and should be confirmed by advanced testing or reprogramming.

Possible Repairs for code P2307 #

Once the root cause of P2307 is found, the appropriate repair can be made. The most common fixes are:

• Replace faulty ignition coil “C”
• Repair or replace damaged wiring/connectors in the coil “C” primary circuit
• Correct short to voltage in the harness (rewire as needed)
• Clean or secure any corroded connectors
• Reprogram or replace the ECM/PCM (only if verified as defective)
• Remove or properly install any aftermarket electronics interfering with ignition wiring

Is it safe to drive with code P2307? #

Driving with code P2307 is not recommended for extended periods. While you may be able to start and move the vehicle, ongoing misfires can quickly damage the catalytic converter and cause further engine issues. At minimum, performance and fuel economy will suffer. If the engine runs roughly or the check engine light is flashing, stop driving and repair the problem promptly.

Vehicles Most Commonly Affected by code P2307 #

P2307 is a generic OBD-II code, but some makes and models are more prone to ignition coil circuit issues due to design or age. Vehicles commonly reported with this code include:

• Ford Focus / Escape / Fusion (2005–2015)
• Chrysler 200 / PT Cruiser / Sebring
• Dodge Caliber / Avenger
• Hyundai Elantra / Sonata
• Kia Soul / Forte
• Toyota Corolla / Camry
• Honda Civic / Accord
• Nissan Sentra / Altima

Common Mistakes & Best Practices for code P2307 #

It’s easy to misdiagnose P2307 if you skip logical steps or overlook simple issues. Avoid these pitfalls:

• Replacing the ignition coil without inspecting wiring/connectors (may waste money if wiring is the true cause)
• Ignoring related codes (misfire or circuit codes can provide important clues)
• Not using OEM wiring diagrams for proper testing
• Assuming the ECM is faulty before checking all other possibilities
• Using low-quality aftermarket ignition coils (can cause recurring issues)

Quick FAQ for code P2307 #

Here are answers to frequent questions about P2307:

• Q: Can I just clear the code and see if it comes back?
  A: You can clear it, but if the root problem isn’t fixed, the code will return. Always address the underlying issue to avoid further damage.
• Q: Can a bad spark plug cause P2307?
  A: No. P2307 specifically refers to the coil’s electrical control circuit, not the spark plug. However, a misfire code may appear alongside if the coil isn’t firing.
• Q: Is this an expensive repair?
  A: Often, fixing P2307 is straightforward—replacing a coil or repairing wiring. ECM replacement is rare and costly, but most repairs are affordable.

In summary: P2307 means the ECM has detected a high voltage in the primary control circuit for ignition coil “C”. Prompt diagnosis—focusing first on the coil and its wiring—can get you back on the road quickly and prevent more serious engine damage.