P2305 moderate

Ignition Coil C Primary Control Circuit High

The P2305 code means the vehicle's onboard diagnostic system has detected: Ignition Coil C Primary Control Circuit High. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$50 - $400 (parts and labor)
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Common Symptoms

  • Misfire detected on cylinder 3
  • Check Engine Light illuminated
  • Engine shaking at idle
  • Sluggish acceleration
  • Exhaust backfiring or popping

Probable Causes (Ranked by Likelihood)

  • Short circuit in coil C wiring harness Very High
  • Internally shorted ignition coil C High
  • Water intrusion in coil C spark plug well Moderate
  • ECM coil driver transistor failed Low

Step-by-Step Diagnostic Procedure

  1. Check spark plug well for water or oil (common leak path for valve cover gaskets)

  2. Swap coil C to verify the fault moves with the coil

  3. Inspect coil C wiring for shorts to power or ground

  4. Measure coil C resistance values

  5. Check valve cover gasket for oil leaking into spark plug tubes

Frequently Asked Questions

Can I drive with code P2305?

Short distances only. Continued misfiring is harmful to the catalytic converter and should be repaired promptly.

What causes P2305?

Often water or oil in the spark plug well causing a short. Check the valve cover gasket and spark plug tube seals if oil is present in the well.

Is P2305 expensive to fix?

Usually $50 to $400. Coil replacement is cheap, but if the valve cover gasket is leaking oil into the wells, that adds to the repair cost.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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