Cylinder 12 Pressure Variation Low
Cylinder-to-cylinder pressure variation on cylinder 12 is below the calibrated minimum — pressure stays unusually constant cycle-to-cycle, often a sign that the closed-loop combustion controller has lost authority or the sensor signal is filtered.
Affected components
- Cylinder 12 combustion
- Cylinder pressure sensor 12
Common causes
- High likelihood: Weak combustion - low cycle-to-cycle variation
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
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.