P3457Cylinder 8 Deactivation/Intake Valve Control Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- 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.
- What you may notice
- Check engine lamp on
- Dynamic cylinder deactivation inhibited
- P3459 may be stored alongside on some GM controllers
- Likely causes
- 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
- RareEngine control module output stage faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.