P3459 code meaning
Cylinder 8 Deactivation/Intake Valve Control Circuit Low
Powertrain system Generic code P34xx codes Check engine light
What P3459 means
When the ground-side control line of the cylinder 8 deactivation solenoid touches ground, the ECM stores P3459. GM publishes this test for the 2019 L84 V8 with Dynamic Fuel Management: driver off, impedance below 0.5 ohm to ground, a minimum of 11 V on the relay feed and 425 rpm, 20 errors in 25 samples, Type B. Some GM controllers log P3457 at the same time. Because a DFM engine may skip any cylinder, a fault on cylinder 8 shuts down a system that otherwise uses this cylinder routinely; GM's LTA and LT2 also include cylinder 8 in their fixed deactivation set. A ground short on the solenoid's high-side feed has its own GM code, P311A. P3460 is the short to power.
P3459 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 P3459
- Check engine lamp on after the second trip
- Engine runs on all eight cylinders at all times
- Higher fuel consumption
Common causes of P3459
- Most likelyCylinder 8 control wire grounded through damaged insulation
- PossibleInternal short in the cylinder 8 solenoid
- Less likelyContamination in the solenoid connector
- Less likelyOutput driver in the engine control module damaged
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 P3459 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). |
| 59 | The exact fault in that area. |
What to do next
- Note P3459 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 P3459
What does P3459 mean?
P3459 means "Cylinder 8 Deactivation/Intake Valve Control Circuit Low". When the ground-side control line of the cylinder 8 deactivation solenoid touches ground, the ECM stores P3459. It is a generic code, so it means the same on every make.
Is it safe to drive with P3459?
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 P3459 fail an emissions test?
Yes, it can. P3459 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 P3459 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 P3459 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.