P3419Cylinder 3 Deactivation/Intake Valve Control Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P3419 says the line feeding the cylinder 3 deactivation solenoid is dragged toward ground. The L84 V8 in GM's 2019 OBD documents shows the test: while the low-side output rests, a resistance to chassis ground under half an ohm is wrong, and once 20 out of 25 readings, one every 250 ms, agree, with the powertrain relay above 11 V and the engine at 425 rpm or faster, a Type B fault is logged. The lamp therefore follows on the second trip, and some controllers add P3417 at the same moment. The older 2007 Displacement on Demand table still merged short and open for cylinder 3 into one solenoid test. P3420 is the opposite fault, P3427 the cylinder 4 equivalent. Driving stays normal apart from the lost fuel saving.
- What you may notice
- Check engine lamp after two drives
- Engine no longer drops cylinders under light load
- Likely causes
- LikelyInsulation of the cylinder 3 control wire worn through to ground
- PossibleInternal short of the cylinder 3 solenoid to its housing
- RareOil or water bridging pins in the connector
- RareDefective driver in the engine control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.