Cylinder 1 Deactivation Stuck On
The engine control module has detected that cylinder 1 remains deactivated when activation is commanded — the deactivation hardware is stuck in the off state. Symptoms include rough running and reduced power.
Affected components
- Cylinder deactivation solenoid
- Lifter
Common causes
- High likelihood: Lifter stuck collapsed
- Medium likelihood: Solenoid stuck in deactivation position
- Low likelihood: Carbon or debris buildup preventing free movement
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
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.