Powertrain, shared range

P3431 Cylinder 4 Exhaust Valve Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3431 reports a cylinder 4 exhaust actuator line shorted to ground. No manufacturer documents this code publicly. Cylinder 4 is switched off by Chrysler's MDS Hemi as well as by GM's V8s with AFM or DFM, but each of them runs a single solenoid per cylinder, so their bulletins and tables only list intake-side circuit codes: Ram's 2025 software bulletin 18-002-25 names P3425 next to P3401, P3441 and P3449, and for GM's 2019 L84, P3427 handles a grounded line of under half an ohm, checked while the output rests and confirmed 20 times in 25 (Type B). That is the closest documented test; CARB would demand the same kind of short detection for a separate exhaust output. Drivers would see the lamp, and cylinder shutdown would cease.

Likely causes

Cylinder 4 exhaust actuator lead grounded on the block or a bracket
Internal short to ground in the exhaust actuator
Control module driver fault

Symptoms

  • Check engine lamp on
  • Engine stays on all 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

P3429P3430P3432P3427P3423P3439

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