The engine control module has detected an open or out-of-range circuit at the cylinder 4 exhaust valve deactivation solenoid. Cylinder 4 cannot be deactivated on the exhaust side until the circuit is restored.
Medium severity. Can I keep driving?Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
Cylinder 4 is numbered according to the manufacturer: check your engine's manual before working on it.
Most likely causes
- Solenoid coil open
- Wiring or connector open
- Pin pushed back out of connector body
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: hard
- It affects emissions.
What each character of P3429 means
- P: Powertrain: engine and transmission
- 3: Generic or manufacturer code, depending on the range
- 4: Emissions
- 29: Specific fault in that system
Frequently asked questions
Can I keep driving with code P3429?
Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.
What causes code P3429?
The most common causes are: solenoid coil open; wiring or connector open; pin pushed back out of connector body.
Related codes
- P3421Cylinder 3 Exhaust Valve Control Circuit/Open
- P3436Cylinder 5 Deactivation/Intake Valve Control Circuit High
- P3414Cylinder 2 Exhaust Valve Control Performance
- P3444Cylinder 6 Deactivation/Intake Valve Control Circuit High
- P3452Cylinder 7 Deactivation/Intake Valve Control Circuit High
- P3460Cylinder 8 Deactivation/Intake Valve Control Circuit High
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.