Powertrain, shared range

P3477 Cylinder 10 Exhaust Valve Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3477 belongs to engines that switch the exhaust valve of cylinder 10 through its own actuator, and it reports that this actuator's circuit is open. No manufacturer documents this code publicly; J2012 reserves the codes for cylinders 9 to 12 for engines with more than eight cylinders. Ten-cylinder engines with shut-off, the Audi R8 V10 and the Lamborghini Huracán, deactivate a bank rather than individual valves; Audi names injection and ignition as what is stopped. GM's patent on valve deactivation shows that the exhaust side has its own timing requirement, with solenoid-driven hydraulic control valves stopping and restarting the exhaust valves ahead of the intake valves. Diagnose as a plain open circuit: connector, wire, coil. P3479 and P3480 are the shorts, P3478 the functional fault, P3473 the intake circuit.

Likely causes

Wire to the cylinder 10 exhaust actuator interrupted
Exhaust actuator coil of cylinder 10 open
Corroded actuator connector
Control module output failed

Symptoms

  • Check engine lamp on
  • Engine keeps all cylinders active

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

P3478P3479P3480P3473P3400P3497

References: law.cornell.edu, patents.google.com, media.audiusa.com, pistonheads.com.