Powertrain, shared range

P3451 Cylinder 7 Deactivation/Intake Valve Control Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P3451 means the switched ground line of the cylinder 7 deactivation solenoid has contact with ground somewhere along its way. GM documents the check for the L84 and L86 trucks and the LT4 Corvette (2019): with the driver off, less than 0.5 ohm to ground, 20 hits in 25 samples taken every 250 ms, Type B, meaning the warning lamp waits for a second faulty trip. According to GM, certain controllers log the open-circuit code P3449 along with it, so both codes together need not mean two faults. On the L84 the high-side feed of the same solenoid reports a ground short under its own code P3117. P3452 is the short to power on this channel, P3450 the mechanical fault.

Likely causes

Cylinder 7 control wire pinched or chafed to ground
Cylinder 7 solenoid shorted internally
Oil or water inside the solenoid connector
Defective driver in the engine control module

Symptoms

  • Check engine lamp on after two trips
  • P3449 may be stored as well
  • No four-cylinder mode, higher fuel use

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

P3449P3450P3452P3455P3400

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