OBD-II code · Powertrain (manufacturer / generic)
P3434 Cylinder 4 Deactivation Stuck Off
The engine control module has detected that cylinder 4 deactivation hardware is stuck in the off state. The deactivation cannot be released when full-cylinder operation is commanded.
Is it safe to drive with P3434?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyLifter stuck collapsed
- PossibleSolenoid stuck
- Less likelyCarbon or debris buildup preventing free movement
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 2–10 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Cylinder Deactivation Solenoid, Lifter
Related codes
- P3406Cylinder 1 Deactivation Stuck Off
- P3412Cylinder 2 Deactivation Stuck Off
- P3431Cylinder 4 Exhaust Valve Control Circuit Low
- P3432Cylinder 4 Exhaust Valve Control Circuit High
- P3433Cylinder 4 Deactivation Performance
- P3435Cylinder 4 Deactivation Stuck On
- P3436Cylinder 5 Exhaust Valve Control Circuit/Open
- P3437Cylinder 5 Exhaust Valve Control Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.