Powertrain, shared range

P3404 Cylinder 1 Deactivation/Intake Valve Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3404 is the short-to-power counterpart within the cylinder 1 group. GM tests it while the low-side driver is switched on: if the output still shows less than 0.5 ohm to supply voltage, the current has no proper path through the solenoid, and 20 of 25 samples at 250 ms set a Type B fault. The test only runs with at least 11 V at the powertrain relay and about 425 rpm (L84; 400 rpm on the L86). Ford names P3404 for the single deactivating cylinder of its VDE engines. Typical culprits are a control wire touching a supply line or a solenoid with shorted windings. Compare P3403 (short to ground) and P3401 (open).

Likely causes

Control wire shorted to a supply voltage in the harness
Shorted winding in the cylinder 1 deactivation solenoid
Damaged output stage in the engine control module

Symptoms

  • Check engine lamp on
  • Cylinder deactivation disabled
  • Possible further circuit codes on other solenoids if a shared supply is affected

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

P3401P3402P3403P3408P3400

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