Powertrain, shared range

P3425 Cylinder 4 Deactivation/Intake Valve Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Cylinder 4 is one of the four cylinders that classic V8 cylinder deactivation shuts off, together with 1, 6 and 7, both at GM (Active Fuel Management) and on the Chrysler 5.7 L Hemi with MDS. That makes P3425 one of the best documented codes in this range. GM's 2019 tables for the L84 and L86 flag an open when the off-state output shows more than 200 kohm, 20 of 25 samples, Type B. Chrysler lists it as Cylinder 4 Deactivation Control Circuit; a STAR case describes the driver-side exhaust manifold heat shield wearing through the solenoid harness and asks for at least 15 mm clearance. P3427 and P3428 cover shorts on the same circuit.

Likely causes

Solenoid harness chafed through by the exhaust manifold heat shield (5.7 L Hemi)
Open coil in the cylinder 4 deactivation solenoid
Corroded or loose solenoid connector
Control module software needing an update (Chrysler TSB 18-002-25)

Symptoms

  • Check engine lamp on
  • Engine stays in eight-cylinder mode
  • Further circuit codes for cylinders 1, 6 and 7 if the shared harness is damaged

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

P3426P3427P3428P3401P3441P3449P3497

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