Engine Pre-Ignition Above Threshold
The ECM detects pre-ignition events (combustion before spark) above the calibrated threshold. Risk of severe engine damage from uncontrolled combustion peaks.
Affected components
- Spark plugs
- Fuel system
- Knock sensor
Common causes
- High likelihood: Low-octane fuel at 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.