Powertrain, shared range

P3463 Cylinder 8 Exhaust Valve Control Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

P3463 would mean that the control line of a dedicated cylinder 8 exhaust actuator is shorted to ground. No manufacturer documents this code publicly. On the only engines with documented cylinder 8 deactivation, GM's L84 and its relatives, one solenoid handles both valves, and GM reports a ground short on it as P3459, testing for less than 0.5 ohm to ground with the driver off. NHTSA's summary of the system lists solenoid driver circuit faults among the reasons the ECM inhibits deactivation, which is also what a driver would notice here: the engine keeps all eight cylinders running and uses a little more fuel. P3461 covers an open, P3462 the function and P3464 a short to power in this exhaust group.

Likely causes

Cylinder 8 exhaust actuator wire shorted to the engine block

Exhaust actuator shorted to ground internally

Driver stage in the engine control module faulty

Symptoms

Check engine lamp on
Engine stays on all eight 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

P3461 P3462 P3464 P3459 P3497

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.