Powertrain, shared range

P3419 Cylinder 3 Deactivation/Intake Valve Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3419 says the line feeding the cylinder 3 deactivation solenoid is dragged toward ground. The L84 V8 in GM's 2019 OBD documents shows the test: while the low-side output rests, a resistance to chassis ground under half an ohm is wrong, and once 20 out of 25 readings, one every 250 ms, agree, with the powertrain relay above 11 V and the engine at 425 rpm or faster, a Type B fault is logged. The lamp therefore follows on the second trip, and some controllers add P3417 at the same moment. The older 2007 Displacement on Demand table still merged short and open for cylinder 3 into one solenoid test. P3420 is the opposite fault, P3427 the cylinder 4 equivalent. Driving stays normal apart from the lost fuel saving.

Likely causes

Insulation of the cylinder 3 control wire worn through to ground
Internal short of the cylinder 3 solenoid to its housing
Oil or water bridging pins in the connector
Defective driver in the engine control module

Symptoms

  • Check engine lamp after two drives
  • Engine no longer drops cylinders under light load

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

P3417P3418P3420P3423P3427P3411

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