XC 90 - Rear Brake Shunt/Relay
 

This is a message for Mark. The attached diagram will show you where you need to look to replace the Rear Brake Light Relay (RMI5).

Let me know if you find success.

Good Luck.

RacerX

Thanks for the swift reply! That diagram doesn't match my 2005, so I did some more digging and found the wiring diagram for the 2005 XC90...unfortunately, it no longer has a brake relay of any sort on the REM. So at this point, I'm still in the dark as to why my left and right brake lights remain on when the ignition is turned off. Disconnecting the brake pedal swith didn't work either. Anybody else have this problem in a 2005 model?

Stop Bulb Issue
 

RacerX,

Can you send me the diagram for replacing the brake relay? When I magnify your attachment from the site it becomes unreadable.

Fiscalsm

Link to diagram
 

I am going to be replacing my relay tomorrow as both of my lights are out and the third light works. The bulbs were replaced and still do not work. I know this post is a bit old but I found a link to the diagram and you can pick the year and make of your Volvo:

http://www.matthewsvolvosite.com/volvo-wiring-diagrams

Take care.

Just reviewed diagram and replaced RMI5 with relay from RMI3 position as it is the same 2270 C2 relay and now my brake lights are working. I do not have deadlocks on the rear doors so I do not need to rush out to the dealer for the relay.

Just an FYI

Malfunctioning brake lights
 

I am having same trouble in my 2001 S-60. LED window brake strip works fine but both L/R brake lamps are out. I have swapped relays and shunts without any change in symptoms.

I have also had a very intermittent problem where rear parking lights stay latched ON after the car is shut off. Pulling out relay RMI5 and re-inserting it clears the malfunction.

I think these two errors are likely related, but not sure where. I will try the lamps, to eliminate gremlins, but the original ones were apparently OK before.

What does a shunt do? When I check with ohmmeter they read zero ohms across all terminals. The schematic shows there is a resistor network across certain terminals but to my meter the unit's terminals all appear joined as one, electrically. Tested 3 shunts, all with same properties.