Just got a 2002 Envoy that has been parked for 2 years. The transmission was slipping so I changed the filter and fluid and it doesn’t slip now, but the only way it will change gears is when the revs get up I have to back of the gas then back on the gas to get it through the gears. But it only works in A4WD, won’t go into 2 wheel. The lights flash back and forth for 2hi but it won’t go in, goes back to 4 wheel. Also there are 2 electrical plugs that are unplugged and all corroded under driver’s door on the frame into a box with what looks like fuel, brake, or transmission lines. Anyone know what these are for. Could they be connected to the transfer case problem in some way? If so what is the name of the part they plug into.
