P3412: Cylinder 2 Deactivation/Intake Valve Control Circuit High

On GM's L84 V8 each cylinder, including cylinder 2, has a valve lifter oil solenoid bolted into the block valley. NHTSA's description of the system notes these solenoids are driven with peak-and-hold current for fast response. P3412 is set when the control line for cylinder 2 is shorted to supply voltage: GM checks it with the driver on and treats under 0.5 ohm to power as failed, 20 of 25 samples at 250 ms, Type B. In that state the computer cannot pull the solenoid properly and drops cylinder 2 from deactivation. Related codes are P3409 for an open circuit, P3411 for a short to ground and P3410 when the circuit is fine but the cylinder does not respond.

Cylinder 2 is numbered according to the manufacturer: check your engine's manual before working on it.

Symptoms

• Check engine lamp on
• Cylinder deactivation no longer active

Most likely causes

• Control wire shorted to a voltage feed in the harness
• Low-resistance coil in the cylinder 2 solenoid
• Engine control module output stage fault

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the oil level and condition before anything else
2. Check the sensor's ground and make sure the signal wire is not receiving voltage from another circuit.
3. Check the solenoid valve's connector
4. Compare commanded and actual angles in live data
5. Test the solenoid valve and its filter, if it has one
6. Check the engine timing if there is chain noise

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P3412 means

• P: Powertrain: engine and transmission
• 3: Generic or manufacturer code, depending on the range
• 4: Emissions
• 12: Specific fault in that system

Frequently asked questions

Can I keep driving with code P3412?

Drive little and gently. If you hear timing chain noise or the oil light comes on, shut off the engine.

What causes code P3412?

The most common causes are: control wire shorted to a voltage feed in the harness; low-resistance coil in the cylinder 2 solenoid; engine control module output stage fault.

Related codes

• P3409Cylinder 2 Deactivation/Intake Valve Control Circuit/Open
• P3410Cylinder 2 Deactivation/Intake Valve Control Performance
• P3411Cylinder 2 Deactivation/Intake Valve Control Circuit Low
• P3416Cylinder 2 Exhaust Valve Control Circuit High
• P3497Cylinder Deactivation System Bank 2

Sources

• law.cornell.edu: 13 CCR 1968.2
• gsi.ext.gm.com: 19OBDG03B Diagnostics
• static.nhtsa.gov: INRD PE25001 11969

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.