Obdaryn

P078BShift Timing Solenoid B Range/Performance

  • Generic OBD-II code · Powertrain
  • Turns on the check-engine light
  • Matters for the ITP
  • Can trigger limp mode
How the car detects it
'Shift timing solenoid' means different parts: on GM's 4L60-E the 3-2 downshift solenoid that times the band apply on that downshift, on Aisin five-speeds (GM, Saab) the linear valve SLS that sets clutch pressure during the shift, and on the 2017–18 Genesis G80/G90 with shift-by-wire the on/off solenoids that engage drive (A) and reverse (B). Only Hyundai/Genesis is documented using solenoid B, and only with the base code P078A. No manufacturer document available to us uses this code; the description follows solenoid A (P0786: current deviation with the circuit intact, on GM's Aisin-type unit more than 80 mA for 2.75 s). Rough shifts and the warning lamp follow.
What you may notice
  • Warning lamp
  • Shift problems
Likely causes
  • LikelyValve or coil faulty
  • PossibleConnector
Inspection (ITP)
Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
Repair
Medium · Usually a job for a workshop.Typical cost: €150 – €900

Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.