Powertrain, shared range

P3449 Cylinder 7 Deactivation/Intake Valve Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3449 tells you the engine computer lost continuity in the circuit to the cylinder 7 deactivation solenoid. Chrysler documents it twice for the 5.7 L Hemi with MDS: a 2025 bulletin for the 2023 RAM 1500 eTorque lists it next to a cylinder 7 misfire (P0307) and fixes it with new PCM software, and a STAR case names P3449 first when the driver-side manifold heat shield has worn through the MDS harness at the rear of the cylinder head. GM uses the code on AFM V8s (L86, LT4 Corvette) and on the DFM L84, flagging more than 200 kohm in the off state, 20 of 25 samples, Type B. P3451 and P3452 report shorts, P3450 a mechanical fault on cylinder 7.

Likely causes

MDS harness at the rear of the driver-side head worn through by the manifold heat shield (5.7 L Hemi)
Cylinder 7 solenoid coil open
Solenoid connector loose or corroded
PCM calibration needing an update (Chrysler TSB 18-002-25)

Symptoms

  • Check engine lamp on
  • Engine stays in eight-cylinder mode
  • Rough idle or misfire on cylinder 7 (P0307) on the 5.7 L Hemi

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

P3450P3451P3452P3453P3441P3400P3497P0307

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