hello friends. I have a 1999 Volvo s80 non turbo 2.9 liter.fwd. automatic trans. started slipping in all fwd. gears but reverse is still fine. my daughter ran thru some rain so I immediately thought of an electrical water short or similar. got the p1618 code of course. this is what I have checked so far:
tcm wiring and especially sensor and solenoid coil ohms. all ohm checks ok so far, also checked gear selector pressure switch (ims I believe) and it checked ok especially in drive and overdrive. ecm wiring physical inspection as I don't have a wiring diagram yet. recently changed fluid and filter myself and did not have hardly any sludge in pan (quite shocking?) mileage is around 189,000+. don't know much history on this vehicle. tried w (winter) mode as well as stc on and off. also noted that when I select stc on the computer panel says stc off? and vice versa? I need a pin out for the ecm to see any problems there? also heard abs module can put vehicle in limp mode but it does not appear to be in limp mode. I cannot drive it to Volvo dealer here in town as it is slipping so awfully.. I just don't want to change it out with a used one and still get the same problem. if anyone has any idea what mechanically and or electrically be wrong or what else I can check. can the epc pressure control solenoid be bad even though it reads good ohms? maybe by me changing fluid and filter it dislodged some sludge somewhere? I will go to auto zone to see if they have a trans. book on the 4t65e? any help would be greatly appreciated!

 

was it power flushed or was the pan just dropped

 

only dropped the pan and shortly after that it quit going in all forward gears.reverse is f
ine.thanks