P3440 code meaning
Cylinder 5 Exhaust Valve Control Circuit High
Powertrain system Generic code P34xx codes Check engine light
What P3440 means
P3440 closes the cylinder 5 block and stands for a high signal, usually a short to supply voltage, in the circuit of a separate exhaust valve actuator. No manufacturer documents this code publicly. The code only makes sense on an engine with a separate exhaust actuator; a Ford patent, for example, checks via exhaust pressure whether an exhaust valve still opens after deactivation. Current production systems that deactivate cylinder 5 drive both valves from one solenoid, and GM reports a short to power there as P3436, checked with the driver on and a 0.5 ohm limit. If a dedicated exhaust channel did short high, the computer would stop using deactivation and light the lamp. Compare P3437, P3438 and P3439.
P3440 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 P3440
- Check engine lamp on
- Cylinder deactivation unavailable
Common causes of P3440
- PossibleExhaust actuator control wire shorted to voltage
- PossibleShorted actuator coil
- 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 P3440 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). |
| 40 | The exact fault in that area. |
What to do next
- Note P3440 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 P3440
What does P3440 mean?
P3440 means "Cylinder 5 Exhaust Valve Control Circuit High". P3440 closes the cylinder 5 block and stands for a high signal, usually a short to supply voltage, in the circuit of a separate exhaust valve actuator. It is a generic code, so it means the same on every make.
Is it safe to drive with P3440?
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 P3440 fail an emissions test?
Yes, it can. P3440 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 P3440 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 P3440 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.