P0757Shift Solenoid B Stuck On
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- A shift solenoid is an electrically switched valve in the valve body; together the solenoid states select the gear, and the module checks the result by gear ratio, slip or a pressure switch – the pattern of wrong gears shows which solenoid hangs off or on. P0757 means solenoid B is commanded off but its clutch stays applied. GM 4-speeds recognise the pattern 1-2-2-1 – third and fourth become second and first – after one trip and switch to third gear with maximum pressure; Allison checks its pressure switch after 2 s. Ford calls it 'functionally failed on' and lists it in bulletins for the 10R80 and 8F35 with mechanical causes. Note that a 2006 GM table labels this row 'stuck off' – the pattern is what counts.
- What you may notice
- No upshift beyond second gear, high engine speed
- Tie-up on shifts
- Limp mode
- Check engine light
- Likely causes
- LikelyShift spool sticking in the applied position
- PossibleSolenoid stuck open or leaking
- PossibleClutch not releasing (burnt or stuck)
- PossibleContaminated or wrong fluid
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €200 – €3,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.