P3485Cylinder 11 Exhaust Valve Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P3485 is triggered by an open circuit on a separate exhaust valve actuator at cylinder 11. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. Bentley's engineers say their W12 shut-off leaves both valve sets working, and they rotate the dormant bank to keep it hot; Lamborghini's Aventador V12 and Audi's group V10 likewise talk only about banks. No published system on an engine of this size switches the exhaust valve of an individual cylinder. A GM patent explains why exhaust timing is a topic of its own: its hydraulic control valves deactivate the exhaust valves first and bring them back first. Electrically, treat P3485 like any open actuator line. P3487 and P3488 report shorts, P3486 a functional fault.
- What you may notice
- Check engine lamp on
- Engine no longer drops to half its cylinders
- Likely causes
- PossibleOpen wire to the cylinder 11 exhaust actuator
- PossibleCoil of the cylinder 11 exhaust actuator open
- PossibleConnector at the exhaust actuator corroded
- RareEngine control module output defective
- 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.