Powertrain, shared range

P3424 Cylinder 3 Exhaust Valve Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3424 closes the cylinder 3 block and stands for an exhaust actuator control line that is held at supply voltage. No manufacturer documents this code publicly. The L84 from GM shows how far one shared solenoid can be monitored without it: for cylinder 3 the ECM checks a low-side driver under P3417, P3419 and P3420 and a high-side driver under extra codes of its own, yet none of them is exhaust-only. A GM patent application explains why: one hydraulic switching valve per cylinder pair serves intake and exhaust, the order being set by the cam lobes. The nearest documented test is the one behind P3420, in which a supply connection of less than half an ohm, seen with the output active, is judged a short. A driver would notice only the lamp.

Likely causes

Exhaust actuator wire chafed against a supply line
Shorted turns in the exhaust actuator of cylinder 3
Engine control module output fault

Symptoms

  • Check engine lamp on
  • Engine runs on all cylinders permanently

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

P3421P3422P3423P3420P3432P3416

References: law.cornell.edu, gsi.ext.gm.com, patents.google.com.