XC90 brake lights stuck on can't determine why?

VolvoXC1973 · Post by **VolvoXC1973** » 12 Sep 2011, 13:55

My wife takes the car out in heavy rain, I come home and the brake lights are stuck on in the garage. I check the fuses, etc. The only way I can get the lights to turn off is to pull the wire harneses in the REM. Message board is telling my check engine system and something about bulb failure, I will get real messages later when I get home. I checked the brake switch under drivers console, seem to work fine but I replaced it anyway, still lights stay on, no resolve, funny thing is even when I unplug the brake switch which you think would be feeding the REM a message to be turning on the lights, the Brake Lights Still are ON. Can't find any other relays, no fuses are blown... could use some assistance if anyone has experience this, not much help from my local Volvo dealer, they want me to drop it off, $$$, I have all the tools and know how to do this if I can and save the $$$. Tonight I'm going to check and see if there is a hot feed coming from the REM as well as the one going to the brake switch.

Post by **brandonbeach14** » 12 Sep 2011, 20:18

Was there any water in the lamp housing? I had the same problem after a severe storm came through last month. I had water in the side the lamp housing. I dried it the best I could and put a couple of tea bags to remove the remaining moisture. The went out the next morning. Hopefully it's this simple for you too. Good Luck

VolvoXC1973 · Post by **VolvoXC1973** » 16 Sep 2011, 07:08

thanks for the advice. I ended up going back and fiddling with the brake switch and adjusting after looking at some other threads and the lights are OFF! Now the service light is on! Many thanks.

fixmyvolvo05 · Post by **fixmyvolvo05** » 05 Jan 2012, 23:43

I have a 2005 XC90 2.5 AWD
Had the 3 rear brake lights stay on for no apparent reason.
I replaced the brake light switch and it seemed to fix the problem. Later that day the lights were on again! Also there was intermittent lights on the dash, wipers would start, front 2 windows wouldn't work. Stop messing with the car and took it to our local mechanic.
After researching I was worried it was the CEM. The mechanic looked into it and went for the CEM. They apparently disconnected the harness and THERE WAS corrosion in the plug. They cleaned it out and put some electrical grease?? all over the plug in case water migrated back down into the area. I also has a bead of black window urethane run along the plastic where the front wind-shield meets the black cover for the wiper area to try and stop any water from entering there. So far everything works great!! This is the nicest car I have ever had but this CEM issue appears to be happening to many Volvo's. There apparently was even a service bulletin issued from Volvo about it. Hopefully it fixes the problem. Cleaning and sealing the existing cem is much cheaper than replacing it.
Cheers, great forum!! Happy New Year!!