P3412 code meaning
Cylinder 2 Deactivation/Intake Valve Control Circuit High
Powertrain system Generic code P34xx codes Check engine light
What P3412 means
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.
P3412 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P3412
- Check engine lamp on
- Cylinder deactivation no longer active
Common causes of P3412
- Most likelyControl wire shorted to a voltage feed in the harness
- PossibleLow-resistance coil in the cylinder 2 solenoid
- Less likelyEngine control module output stage fault
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cylinder deactivation solenoidWiring harnessECM
What each part of P3412 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 3 | Mixed range: generic and manufacturer-specific codes. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 12 | The exact fault in that area. |
What to do next
- Note P3412 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P3412
What does P3412 mean?
P3412 means "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. It is a generic code, so it means the same on every make.
Is it safe to drive with P3412?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P3412 fail an emissions test?
Yes, it can. P3412 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P3412 to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P3412 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.