P2312 moderate

Ignition Coil G Primary Control Circuit Low

The P2312 code means the vehicle's onboard diagnostic system has detected: Ignition Coil G Primary Control Circuit Low. This is a moderate severity code.

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Keep driving?
Short distances only
DIY difficulty
moderate
Estimated cost
$50 - $350 (parts and labor)
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Common Symptoms

  • Engine misfire on cylinder 7
  • Check Engine Light flashing
  • Noticeable engine roughness
  • Reduced power output
  • Raw fuel smell from exhaust

Probable Causes (Ranked by Likelihood)

  • Failed ignition coil G Very High
  • Damaged wiring to coil G High
  • Corroded coil G connector Moderate
  • Fouled spark plug on cylinder 7 Moderate

Step-by-Step Diagnostic Procedure

  1. Swap coil G with another cylinder coil to confirm the fault

  2. Inspect and replace the spark plug on cylinder 7

  3. Check coil G connector for corrosion

  4. Measure coil G primary resistance

  5. Inspect the wiring harness for heat damage from exhaust

Frequently Asked Questions

Can I drive with code P2312?

Short distances only. A misfire on one cylinder of a V8 may feel less severe but still damages the catalytic converter over time.

What causes P2312?

A failed ignition coil on cylinder 7. On V8 engines, consider replacing all 8 coils as preventive maintenance if mileage is above 100,000.

Is P2312 expensive to fix?

Typically $50 to $350. V8 ignition coils are inexpensive. Replacing all 8 as a set is cost-effective and prevents future failures.

Sources

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

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