Our '09 s80 has been acting up and apparently the rear brake module PN 31445647 is not being seen by the main control module. The brake is not enguaged so its not a problem to drive. We took it into the Volvo dealer and they had up replace the car's main control module for $2000 but it did nothing. I bought the rear brake module used and now need to know where the heck it is in the car and also how I swap it out. After that, back to the dealer for reprograming ($750) the system to use the new module if it just doesn't magically work. Any guidance would be appreciated.

 

1. There's no warranty on their work? If the new CEM/BCM did not fix it - have them put your old one back in, and refund your money. Unless they were instructed to replace a part that did not fix it - you should not be responsible for their mistake. Perhaps you should pay for some (incorrect) diagnostic time - but not for a new control unit that did not fix it.
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3. Most modules, if they are "coded" to the VIN - can only be coded when they are new. Usually Vida can't "recode" a used part. But it's possible a used one might work, I have not tried. Have you verified Volvo can do this for you? And a software download is usually about an hours labor plus the less than $100 software charge. How did you get a $750 price? I'd bet the $750 price is for a NEW PBM installed and programmed to your car. ( since that part number is about $400)

Here's some of the PBM codes. What codes are stored in your car? Or are you just replacing parts hoping to fix something?

 

They described the thing as "Try this first as we are not sure how to fix it, if that does not work then replace the brake module". I took their advice and approved the try. My mistake, but nobody around here can effectively work on Volvos, so they have a corner on the market for electronic systems service. They said that they could reprogram the module if I found a used one. I'm going to attempt to connect the new part and see if it works. I doubt it will.

Thank you for the location!! Going to work on it now.

 

Update 3/16/23: I found the rear brake module, but did not swap it out. When I looked at the part number that was originally in the car, it was a different product code. I called the dealership and they said that these have been superseded several times and the one they provided was the latest (no wonder I had trouble finding one used). When I pressed as to whether it would work, they had no clue. They said that some of these parts are hard coded to the car (Like the central computer that I replaced for $2K). So I pressed some more and they relented and said they would try it and not charge me if it did not work. So I had nothing to lose. They put it in and it worked after reprogramming!!!. So these rear brake modules are not hard coded to the car at the factory!

I paid $54 for the used rear brake module and $420 for software and reprogramming. I got away for under $500 (not including the original $2k I spent with them. They quoted me $750 for a new module and installation/programming was $400. So if you have the same issue, buy a used one and save a lot of money. And don't do what I agreed to do and replace the entire computer in the car. That was a waste.

 

You need find pbm with the same number, which means the same software, otherwise it works fine physically, but your dash will have error message.

 

I ended up finding one on Ebay for $54 and the dealership was able to reprogram it. I took a chance and it worked. It messed up more than just the rear brake for some reason, but all that started working again as well.

 

I can't help you as well as hoonk but I can sympathize with you. I also own a 09 S80 and when a costly repair comes up I use to question if it's worth it. Several years ago I was considering purchasing a new Volvo. My wife said 'how much is the monthly payment?', my answer 'likely about $1000'. Then she asked 'how much would it cost per month to maintain our 2009?'. I said, 'at the max $400 a month or somewhere between $3000 and $5000 a year. The answer was obvious, keep the 2009.
The last 2 years I have seen a lot of items come to the end of their life, it was a rash of things, something expensive every few months.
So over the last 26 months the following work was done: All new parts nothing used and all top of the line and or OEM. New AC compressor and refrigerant charge,
4 new summer tires, 2 winter tires, strut mounts, Cat converter, battery, front and rear sway bar links, water pump, belt tensioner, idler pully & belt, AWD Coupling oil pump, front and rear brake pads, all rotors, front calipers, change brake fluid, multiple oil and air filter changes, hood lift supports, both front control arms complete with ball joints, 2 alignments, and likely 3 or 4 smaller things like bulbs etc. The S-80 is a very nice car. I choose it for long distance driving over my Mercedes or my SAAB.
Enjoy the car and safe driving.