P3427Cylinder 4 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
- P3427 is set when the cylinder 4 deactivation solenoid circuit has a path to ground. GM uses it on several 2019 V8s: the DFM engine L84, the AFM engine L86 and the LT4 of the Corvette. Once the low-side output is switched off, less than half an ohm toward ground fails the check; 20 of 25 samples, relay voltage at least 11 V, 425 rpm (L84) or 400 rpm (L86, LT4), Type B. In all three tables the criteria column names cylinder 1, an apparent copy slip. For the MDS-equipped Hemi from Chrysler, one STAR case documents an exhaust manifold shield that rubs the solenoid harness open; a bared wire touching metal there can end up as this kind of short. P3428 covers the opposite short, to battery voltage.
- What you may notice
- Check engine lamp after two drives
- V4 or reduced mode never engages
- Further circuit codes on other deactivating cylinders if the harness is damaged
- Likely causes
- LikelyControl wire to the cylinder 4 solenoid rubbed through to ground, e.g. by a heat shield
- PossibleCylinder 4 solenoid shorted internally
- RareMoisture or oil in the solenoid connector
- RareDamaged 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.