P3489Cylinder 12 Deactivation/Intake Valve Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P3489 reports that the circuit to the actuator for deactivation or the intake valve of cylinder 12, the highest cylinder number in this code series, is open. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. Twelve-cylinder engines with shut-off span Mercedes' late-1990s V12, which deactivated every second cylinder in the firing order, Lamborghini's Aventador V12 that shuts down one cylinder bank below 135 km/h, and Bentley's W12. The Mercedes engine used a hydraulic solenoid pack, the kind of part such a circuit would drive; the bank-based systems publish no equivalent. Comparable logic on GM V8s calls a circuit open above 200 kohm with the output idle. P3491 and P3492 report shorts, P3490 a functional fault, P3493 the exhaust valve.
- What you may notice
- Check engine lamp on
- Engine no longer runs in reduced-cylinder mode
- Somewhat higher fuel use on the highway
- Likely causes
- LikelyWire to the cylinder 12 actuator open or chafed
- PossibleCylinder 12 actuator coil open
- PossibleLoose or corroded connector at cylinder 12
- RareOutput stage of the control module failed
- 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.