P349F: Cylinder 8 Deactivation/Intake Valve Performance

Per-cylinder intake valve deactivation on cylinder 8 does not respond as commanded.

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 8 is numbered according to the manufacturer: check your engine's manual before working on it.

Most likely causes

Actuator stuck mechanically

What to check, in order

Start with the simplest. You can tick off each step.

Check the oil level and condition before anything else
Compare the reading with other engine data while varying the engine speed.
Check the solenoid valve's connector
Compare commanded and actual angles in live data
Test the solenoid valve and its filter, if it has one
Check the engine timing if there is chain noise

Good to know

Repair difficulty: hard
It affects emissions.

What each character of P349F means

P: Powertrain: engine and transmission
3: Generic or manufacturer code, depending on the range
4: Emissions
9F: Specific fault in that system

Frequently asked questions

Can I keep driving with code P349F?

Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.

What causes code P349F?

The most common causes are: actuator stuck mechanically.

Related codes

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.