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.
Installing a new rebuilt transmission without doing the following is fruitless: Full transmission fluid flush Go to a dealer or Volvo indie shop to get rid of the stop neutral transmission “feature” Clear and reset all the adaptions And do a new drive cycle Whenever the transmission is overhauled or replaced, the valve body is […]
Another Volvo Forum topic regarding the death of a 2001 Volvo automatic transmission, this one with some insight by those with either mechanical and Volvo sales backgrounds. Just to let everyone know, I (ME) was the beta tester for the stop/neutral software. I had an early 01 (new) with almost immediate clunking issues. I complained […]