Powertrain, shared range

P3442 Cylinder 6 Deactivation/Intake Valve Control Performance

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modeNo

P3442 reports that cylinder 6 does not switch off or back on as commanded although its control circuit tests fine. FCA uses it as Cylinder 6 Deactivation Control Performance on the 6.4 l Heavy Duty Hemi with MDS in RAM 2500 to 5500 trucks: bulletins 18-082-16 and 18-036-20 list it with P3402, P3426 and P3450 under a lit MIL and fix it with new PCM software. Ford stores it on 2025 F-150 5.0 l trucks built January to April 2025: bulletin 25-2487, replaced by 26-2093, traces P3442 and P3450 to a restricted oil feed tube for the left-bank deactivation solenoids, which is renewed under the valve cover. GM's L84 judges cylinder 6 under its own code P349D. Electrical faults on the same channel are P3441, P3443 and P3444.

Likely causes

Outdated PCM calibration (FCA 6.4 l, bulletins 18-082-16 and 18-036-20)

Restricted oil feed tube to the left-bank solenoids (Ford 5.0 l, TSB 26-2093)

Oil level too low, wrong grade or worn oil, so pressure builds too slowly

Deactivating lifter of cylinder 6 not locking or unlocking

Symptoms

Check engine lamp on
Jerk or vibration when the engine changes between eight and four cylinders
Misfire on cylinder 6 (P0306)
Fuel consumption rises because deactivation is locked out

Repair estimate

DifficultyHardWorkshop job

Parts and labour€100–3,500

Time0–12 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

cylinder deactivation solenoidlifterengine oil

References: law.cornell.edu, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.