Wondering if you need to change the transmission fluid in your P1 generation — 2004-2012 — Volvo S40/V50? MVS user cleve33 had a similar question after his mechanic recommended every 30k miles and worrying it was just a cash grab. Turning to the good people of the MVS forum, he asked how often to change […]
Neutral control bump is the result of the pulsed solenoids getting bore wear and the pulsed signal outputted by TCM is not really getting the pressure regulation desired. There is no pressure sensor so the TCM infers pressure through its adaptive shift control, i.e., if the shift is completed within the target time with X% solenoid signal then .5X% should be the right signal to reduce clutch apply pressure to let it slip during N control and not have slam engagement when brake is released. With worn solenoid or valve body spool valve bores the pressure with that reduced signal is not what is inferred via software.