P3499Cylinder 2 Deactivation/Intake Valve 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
- P3499 reports that cylinder 2 did not stop exchanging gas when told to deactivate. On GM's DFM V8s (L84, L87) one oil solenoid in the lifter valley feeds both lifters of the cylinder; oil pressure pushes spring-loaded pins inward which lets the outer lifter shell ride the cam while the valve remains closed. If those pins stay engaged, the engine computer sees manifold pressure that is too high during the skipped events and, after 22 of 25 failed opportunities, stores this Type B code. GM's 2019 Silverado and Sierra information PIP5584 names a faulty oil control solenoid as one cause. The electrical side of cylinder 2 has its own codes (P3409, P3411, P3412), and the control-performance code is P3410. Expect a lamp and lost economy.
- What you may notice
- Check engine lamp on
- Higher fuel consumption because cylinder 2 is no longer skipped
- Ticking from the lifter area
- Likely causes
- LikelyLocking pins in the cylinder 2 lifters do not retract
- PossibleLifter oil solenoid of cylinder 2 not delivering oil pressure
- PossibleLow, aerated or degraded oil
- RareCode stored without a real fault, ECM software update needed
- 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 – €4,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.