Powertrain, shared range

P3447 Cylinder 6 Exhaust Valve Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3447 is about a ground fault on the lead of a stand-alone exhaust actuator for cylinder 6. No manufacturer documents this code publicly. GM, the one maker publishing the full set of cylinder 6 circuit codes, switches both valves of the cylinder with one solenoid and reports a ground short as the intake-side P3443: impedance below 0.5 ohm toward ground while the driver is off, 20 of 25 samples, Type B. A comparable test would apply here, because CARB requires circuit monitoring for every emission-relevant output. NHTSA notes that GM inhibits deactivation as soon as a solenoid driver circuit fault is present, so the practical result is an engine running on all cylinders. P3445 (open) and P3448 (short to power) are the neighbouring exhaust codes.

Likely causes

Exhaust actuator wire of cylinder 6 chafed against the engine
Internal short to ground in the exhaust actuator
Damaged driver in the engine control module

Symptoms

  • Check engine lamp on
  • Engine stays in full-cylinder mode

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

P3445P3446P3448P3443P3497

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