I have a 2006 s60 and the brake lights stay on. It started off with the bottom 2 brake lights didn't fire when pressing the brake pedal, which turned into all the brake lights staying on even when the car is off. When the bottom lights weren't firing, I was getting the message to check the brake lights, but when all the lights stayed on I was not getting the message to check the brake lights. I changed out the brake switch but nothing changed and the lights are still on. I unplugged the relays and it doesn't look like either was corroded. I found the relay that was in charge of the lower two, because the lower lights turned off when it was unplugged but the third stayed on. After unplugging the relay for the third light, I plugged them all back in, and the lower lights are off when the relay controlling them both is plugged in, but when the relay for the third light is plugged in all three stay on. Trying to see if there is anything else I should try before I take it to a dealer to replace the CEM. Any thoughts? Thanks in advance!

 

Check the relays in the REM in the rear - this is where the brake lamp relay is located (common failure)