Powertrain, generic · Transmission

P0757 Shift Solenoid B Stuck On

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Shift spool sticking in the applied position
Solenoid stuck open or leaking
Clutch not releasing (burnt or stuck)
Contaminated or wrong fluid

Symptoms

  • No upshift beyond second gear, high engine speed
  • Tie-up on shifts
  • Limp mode
  • Check engine light

Repair estimate

DifficultyHardWorkshop job
Parts and labour€200–3,500
Time2–12 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

shift solenoidtransmission valve bodytransmission wiringtransmission control module

Related codes

P0756P0755P0758P0733P0734P0976

References: gsi.ext.gm.com, gsi.ext.gm.com, gsi.ext.gm.com, newtonnet.co.uk.