Powertrain, shared range

P3485 Cylinder 11 Exhaust Valve Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

Likely causes

Open wire to the cylinder 11 exhaust actuator
Coil of the cylinder 11 exhaust actuator open
Connector at the exhaust actuator corroded
Engine control module output defective

Symptoms

  • Check engine lamp on
  • Engine no longer drops to half its cylinders

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–900
Time0.5–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

cylinder deactivation solenoidwiring harnessecm

Related codes

P3486P3487P3488P3481P3400P3497

References: law.cornell.edu, mobilityengineeringtech.com, patents.google.com, newatlas.com.