Engine Pre-Ignition Above Threshold - Forced Limited Power
Pre-ignition events exceed a critical threshold. The ECM forces limited engine power to protect pistons, rings, and connecting rods from further damage.
Affected components
- Spark plugs
- Fuel system
- Ecm
Common causes
- High likelihood: Low-octane fuel under sustained high load
- Medium likelihood: Carbon deposits glow as hot spots
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- Reduced-power or limp mode may occur
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.