P2318Ignition Coil G Primary Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2318 says the command wire of coil G, cylinder 7, is touching ground, so it only occurs on V8, V10 or V12 engines. GM's 2019 table for the 5.3-litre L84 truck V8 lists it as a Type B code (50 of 63 failed samples, battery above 11 V, MIL after two trips). Ford covers the series up to P2327 for its V10 and adds that the PCM cuts the injector of the affected cylinder; special service message 52455 (2024) for the 6.8 and 7.3-litre petrol engines in Super Duty, F-53/F-59, E-Series and F-650/750 trucks names P2318 among codes the PCM may pin on the wrong cylinder, so a power balance test should confirm which cylinder really drops out. Open-circuit faults on coil G use P0357, misfire on cylinder 7 is P0307.
- What you may notice
- Check engine light on
- Misfire on cylinder 7
- V8 runs noticeably rough, power reduced
- Likely causes
- LikelyCoil G (cylinder 7) defective
- PossibleWater or corrosion at the coil G connector
- PossibleControl wire of coil G grounded by heat or chafing damage
- RarePCM cylinder mapping error on Ford 6.8/7.3 (SSM 52455)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.