P2318Ignition System
Ignition Coil G Primary Control Circuit Low
P2318 means the ECM detected low voltage on the primary control circuit for ignition coil G. The cylinder served by coil G is likely misfiring.
🚗 Not recommended. The affected cylinder is misfiring and can damage the catalytic converter.
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🎯 Top Causes, Ranked by Likelihood
#1Failed ignition coil (cylinder G)$30-$120
Internal primary winding fault in the coil unit.
#2Wiring or connector fault at the coil$40-$250
Damaged connector, chafed wire, or bad ground.
#3ECM driver circuit fault$200-$900
Rare failure of the coil driver in the ECM.
🩺 Common Symptoms
- Single cylinder misfire
- Rough idle and shaking
- Check engine light, may flash
- Loss of power
- Poor fuel economy
💰 Repair Cost: DIY vs Shop
📋 Free OBD2 Code Cheat Sheet
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🔧 How to Diagnose P2318
1Find which cylinder coil G serves on your engine
2Swap the coil with an adjacent cylinder to test if the code follows
3Inspect the coil connector and wiring
4Replace the coil if it is the source
❓ Frequently Asked Questions
Can I drive with P2318?
Not for long. A misfire can overheat and ruin the catalytic converter.
How much to fix P2318?
A single coil is $30-$150 DIY, or $120-$400 at a shop.
Does P2318 mean a bad coil?
Usually. Confirm by swapping the coil to another cylinder before replacing.
🔗 Related Codes
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