P3434Cylinder 5 Deactivation/Intake Valve Control Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- With P3434 the computer has found that cylinder 5 does not switch off or back on correctly, while the control circuit tests fine. No manufacturer documents this code publicly. GM's L84 runs the equivalent test under P349C: manifold pressure stays too high while cylinder 5 is commanded off, meaning its valves keep working. For 3.6 L V6 engines, GM bulletin 21-NA-036 describes the field picture: misfires on cylinder 5 (P0305), sometimes only after a reduced-cylinder phase, from oil leaking past the control valve or rockers that do not latch, and asks to check for a solenoid tip broken off in the bore. Wiring faults for this cylinder are P3433, P3435 and P3436.
- What you may notice
- Misfire on cylinder 5 (P0305)
- Check engine lamp on
- Shaking after reduced-cylinder operation
- Likely causes
- LikelyOil leaking past the cylinder 5 control valve seal
- PossibleSwitching rocker or lifter of cylinder 5 not latching
- RareSolenoid tip broken off in the bore
- RareLow or aged engine oil
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.