This fix is very similar to what what phat78ta wrote up here:
https://www.matthewsvolvosite.com/forums ... =1&t=27239
I pay homage to you phat78ta, you made my path clear!
All I'm offering here that goes a little farther is more pictures and more detail in some areas, including the LED code reader (if you need it... you need it if you have ECC and a '96 or '97 850 with OBD2).
The LED code reader will help you figure out which code you have. Others have written up how to make one of these -- I added my contribution here: https://www.matthewsvolvosite.com/forums ... 43#p251189
The code reader I made is very simple. It looks like this: Once I had the code reader working I got the 2-1-1 code, meaning "Driver's side damper motor position sensor open circuit or shorted to 12 Volts". I wasn't too sure what this meant but I figured it would be a good idea to take the driver's side damper out and inspect & investigate it. It is way up under the dashboard on the driver's side, above the cruise control actuation diaphragm. You have to remove the lower plastic trim panel (T-25) and the black metal anti-submarining bolster (6 point 13mm).
I needed a small mirror and a couple of flashlights handy to get it out. You have to remove three short T15 screws and the electrical connector (which has two clasps that must be pried outwards simultaneously -- I used small flat blade screwdrivers to do this). There is not a lot of room so slide the driver's seat all the way back and be prepared to lie on your belly and your back to get it done.
Once you get the damper out of the car, mark the position of the shaft relative to the case: Then there are three phillips screws to remove and four black plastic clasps to fold back (three of the four of mine cracked when folded back -- they're not critical) and the case can be opened: Then you can lift up the large central white plastic gear to reveal all the grease you are going to need to remove Note that the backside of the gear has fine copper-colored metal contacts -- don't bend them: Clean off all the grease from the black contact areas. I used a paper towel to remove most and then MAF cleaner (hexane, mostly because I already had it at hand in the workshop) to remove the residuals: Then you have to put the plastic gear back in place, aiming the clocking mark you made on the shaft into the approximate position to align with the case. I also took the opportunity at this time to apply a very small amount of white lithium grease onto the teeth of the gears. Then you place the top cover loosely over the bottom body of the case and look to see if you've got the white plastic gear in the correct position. If not, lift up the white gear, rotate it into the right position and re-engage it with the small drive gear. Once you've got it aligned to the right position, put the cover back on. Clip the plastic clasps back in place and you're ready to re-install the three phillips screws. Then it's back to the car and squeezing under the dashboard again. The picture below was taken lying on my back looking from the footwell up towards the bottom of the dashboard. The screws and damper shaft positions are shown here: I put the front-most screw in place first because it's the easiest: To get screw #2 and #3 in place, I found a little piece of my son's playdoh invaluable (green is my favorite color) to hold the screws onto the bit while I was maneuvering. You could use chewing gum too. With the screws in place, re-attach the electrical connector and replace any other pieces you may have disconnected to improve access (I disconnected one of the cruise control vacuum line elbows from the diaphragm because it was in the way).
It's not easy to get a photo of the damper in place because access is limited.... this was the best I could do: Then you turn the ignition on and check codes again. In my case, the car was happy... it had given the "2 1 1" code before the repair. Once I installed the cleaner damper motor and checked the codes again, the ECC unit had cleared the "2 1 1" by itself and was reporting "1 1 1" -- "all good".
Good luck!








