I read somewhere that on a 98 gmc its usually an NSBU sw on left side of transmission costs around $90. a couple of dollars less at an Allison dealer. not sure what that switch is but sounds like maybe could be similar to the Chrysler solenoid pack with similar price that can cause similar problems. dont take it as gosple. I just saw it while researching similar problem and thought id pass it along, and maybe it'd be useful to look at.
The GMC Sonoma 2.2 litre manual transmission hold 12 quarts of transmission gear oil. Keep in mind there is a big difference between gear oil and automatic transmission fluid.
The transmission fluid capacity for a 2000 GMC Jimmy is six quarts. Transmission fluid should be added slowly to because capacity can be reached rapidly.
for manual only, do not use gear oil in automatic transmission 80W-90gl-5 4spd gl-4 transmission fluid
automatic
Is your transmission fluid full?
change your transmission fluid and transmission filter if the problem persists then your transmission is most likely no good.
16
4l60e
You should change the transmission fluid and filter on a 2000 GMC Yukon every 5,000 to 6,000 miles. It does not need changes more frequently than that.
The governor is stuck.
0w80 synthetic gear oil.
It should be marked right on the dipstick what fluid to use.