Powertrain, shared range

P3435 Cylinder 5 Deactivation/Intake Valve Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3435 flags a short to ground on the control line of the cylinder 5 deactivation valve. GM documents it codewise twice: in the 2019 tables for the L84 V8, with under 0.5 ohm to ground in the driver-off state, 20 of 25 samples at 250 ms and Type B, and in an engineering bulletin for 3.6 L V6 engines (LGX, LGZ) where P3435 appears along with P3433 and P3409 when oil leaks from the rocker arm control valve. Oil that wicks into the connector can create exactly such a leakage path. P3433 is the open circuit, P3436 the short to power, P3434 a mechanical failure. In daily driving the engine simply stays on all cylinders.

Likely causes

Oil in the cylinder 5 valve connector creating a leakage path (GM 3.6 L V6)
Control wire shorted to ground
Shorted cylinder 5 solenoid
Engine control module driver fault

Symptoms

  • Check engine lamp on
  • Oil wetness at the valve cover around the control valve (V6)
  • No fuel-saving cylinder deactivation

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

P3433P3434P3436P3439P3409P3400

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