Rear Brake Lights Not Working 2010 XC90

usmctanker · Post by **usmctanker** » 31 Aug 2012, 17:48

Hi- I recently got a "check stop lamp" warning on my 2010 XC90. When I checked the rear brake lights, I discovered that the brake lights in the tail lights were not working, however, the "third eye" center stop lamp works fine. Replaced both bulbs, no luck. Checked all fuses - all good. Checked for current at the lamp with a multi-meter, no current with pedal depressed.

I read in another post on this site where the problem could be a shunt relay at the REM; when I took out my REM however, there are no shunts or relays that are readily apparent, just fuses and two wiring harnesses in the front and one in the back. I went ahead and ordered a couple of brake lamp relays for my make and model, but I will be hung if I can figure out where they are located on the 2010 XC90. Any one got any ideas or some pointers? Thanks much. My other car is a '66 Mustang... there are more wires coming out of that Volvo REM than there are in total on that car!

Post by **jimmy57** » 31 Aug 2012, 22:28

The lighting on 2005 and later Volvos is transistorized and if there is a short the circuit is shut down. You should see a dealer and let them read codes and see what ails it since it is not the bulbs.

Tony1979 · Post by **Tony1979** » 01 Sep 2012, 05:49

Trust me it won't be the fuse or bulbs, it'll be either the brake light switch on the foot pedal playing up or what I've come across in the past the brake light relay.

On my 2001 S60 it was relay RM15 in the "REM" the rear electronic module in the boot/trunk of the car, open the plastic cover on the nearside and voila!

Tony1979 · Post by **Tony1979** » 01 Sep 2012, 06:01

I'm pretty sure your car is the same set up as mine, you can get the relay for a few pounds/dollars on eBay, it needs to have 9441161 on it though.

Try swapping RM16, the rear fog light relay over to see if it is faulty. If it is I would from a safety aspect run with no fog lights until you get a new one.

Have fun playing

usmctanker · Post by **usmctanker** » 01 Sep 2012, 09:22

Thanks Tony, thank Jimmy.

Tony - when I go over photos of older Volvos, you can clearly see relays on the REM. On mine, there simply are none, although a car parts place had no problem selling me a relay for a 2010 for ~$12. I thought about the foot pedal switch as that seems to be a trend with Volvos, but I thought if that was acting up, I would not get the high stop lamp.

Jimmy - you highlighted what I was afraid of, as it looked like the REM had to have a number of internal components and that there is some short somewhere that I wont be able to find without help. I just hate going to the dealer for anything. I have done just about everything you can to a car (rebuilt motors, trannies, brakes, suspension) and it bugs me to have to trust some one else. Oh well, guess it is time to quit crying and take it in before I make it worse.

Tony1979 · Post by **Tony1979** » 01 Sep 2012, 14:18

I'm sure you have the REM I might be wrong?!

Try this link and scroll down to page 33

http://www.google.co.uk/url?sa=t&source ... CbWml-fa3Q

Tony1979 · Post by **Tony1979** » 01 Sep 2012, 14:29

You should have fun with this usmctanker

http://www.google.co.uk/url?sa=t&source ... 0N2Oh8sqog

usmctanker · Post by **usmctanker** » 02 Sep 2012, 11:24

Tony- Thanks for sticking in there with me. Those are great resources.

I think I have a decent understanding of how the brake lights are wired, but unless the relay is inside the REM itself, I have no idea what to replace. I expected the relay to simply be plugged into the REM esternally, and I could simply take it out and put in a new one as one would do with a typical relay. However, as Jimmy said at the outset of this thread, the relays appear to be transistors inside the REM. I started to open the REM box, but then common sense got the better of me. Here is a picture of my REM out of the car (at least I have tried to). Am I missing the boat?
http://i1160.photobucket.com/albums/q49 ... 22e7a4.jpg

Thanks again!
Steve

usmctanker · Post by **usmctanker** » 04 Sep 2012, 20:29

Well everyone... Yesterday I lost anti-skid control, battery/generator light, got an urgent electrical service warning, and lost automatic door locks. Took it into the dealer and he confirmed what we thought - bad REM. $138 for the diagnostic, $648 for the new REM, $99 for new software load, plus labor for $1200. Car is 2 years old with 56k miles. Last Volvo I will buy I think. Thanks for the help everyone.

Tony1979 · Post by **Tony1979** » 05 Sep 2012, 03:05

Sorry about the news, ouch that is expensive!
That is rare in such a new car.