P3462: Cylinder 8 Exhaust Valve Control Performance

With P3462 the ECM would be saying that the exhaust valve of cylinder 8 ignores deactivation commands even though nothing is wrong electrically. No manufacturer documents this code publicly. GM covers the exhaust side of cylinder 8 on the 2019 L84 with its own code P3190, Cylinder 8 Trapped High Pressure Exhaust Charge: if crankshaft jerk, normalized by engine speed, exceeds a load-dependent threshold while the cylinder is deactivated, the exhaust valve is judged not to have opened, and 66 failures in 100 samples set a Type B code. Ford patented the complementary check for an exhaust valve that keeps opening after deactivation, based on exhaust pressure. Symptoms range from vibration in reduced-cylinder mode to a misfire on cylinder 8 (P0308).

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.

Symptoms

Check engine lamp on
Vibration while cylinders are deactivated
Misfire on cylinder 8 (P0308)

Most likely causes

Exhaust lifter of cylinder 8 failing to relock in time
Oil supply to the lifter gallery insufficient
Exhaust-side control valve sticking

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 P3462 means

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

Frequently asked questions

Can I keep driving with code P3462?

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

What causes code P3462?

The most common causes are: exhaust lifter of cylinder 8 failing to relock in time; oil supply to the lifter gallery insufficient; exhaust-side control valve sticking.

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.