P3457 code meaning
Cylinder 8 Deactivation/Intake Valve Control Circuit/Open
Powertrain system Generic code P34xx codes Check engine light
What P3457 means
Cylinder 8 is not among the cylinders that classic Active Fuel Management or Chrysler's MDS shut off (both use 1, 4, 6 and 7), so P3457 is documented only for newer designs. GM's 2019 tables list it for the L84 with Dynamic Fuel Management, which can deactivate every cylinder: more than 200 kohm with the low-side driver off, 20 of 25 samples every 250 ms from 425 rpm, Type B. GM's AFM/DFM information bulletin adds that the LTA and LT2 engines deactivate cylinders 2, 3, 5 and 8. GM also notes that some controllers store P3459 together with an open. P3458 is the function code for cylinder 8, P3459 and P3460 the short-circuit codes.
P3457 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 P3457
- Check engine lamp on
- Dynamic cylinder deactivation inhibited
- P3459 may be stored alongside on some GM controllers
Common causes of P3457
- Most likelyWire to the cylinder 8 solenoid broken or chafed in the lifter valley harness
- PossibleOpen winding in the cylinder 8 solenoid
- PossiblePoor contact at the solenoid connector
- Less likelyEngine control module output stage faulty
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 P3457 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). |
| 57 | The exact fault in that area. |
What to do next
- Note P3457 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 P3457
What does P3457 mean?
P3457 means "Cylinder 8 Deactivation/Intake Valve Control Circuit/Open". Cylinder 8 is not among the cylinders that classic Active Fuel Management or Chrysler's MDS shut off (both use 1, 4, 6 and 7), so P3457 is documented only for newer designs. It is a generic code, so it means the same on every make.
Is it safe to drive with P3457?
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 P3457 fail an emissions test?
Yes, it can. P3457 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 P3457 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 P3457 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.