V50 brake lights on permanently !

[nobananas]

Hi all. Got a customer at work with an odd issue. The brake lights on his 05 V50 are on all the time, even when the vehicle is locked up !. It's not the brake switch as the problem remains even when it's unplugged, the fault also remains when various rear lights are unplugged as well as the tailgate loom. I'm thinking the fault may be down to the CEM (fusebox) as a wiring diagram shows the CEM taking a signal from the brake light switch then 3 separate feeds from 3 separate multiplugs feeding the 3 brake lights. Anybody had any similar problems like this ?

[Dangerous Dave]

Corrosion on the CEM connections? apparently there's some issues with the connectors corroding due to water ingress.

http://www.volvoforums.org.uk/showthread.php?t=268807

[nobananas]

Corrosion on the CEM connections? apparently there's some issues with the connectors corroding due to water ingress.

http://www.volvoforums.org.uk/showthread.php?t=268807

Thanks Dave. Have checked that already, had the CEM out at least a dozen times now, even cracked it open to check for dry joints or corrosion on the board but can found nowt obvious.

[Dangerous Dave]

Hmmm, intriguing :)

[nobananas]

Hmmm, intriguing :)

Damn annoying is what it is !. They also occasionally go off at random making you think that that wire or connection you just wriggled was the cause then after an hour of checking every wire and connection nearby you realize that it was just a coincidence and they're still on !

[Dangerous Dave]

CEM sounds buggered, especially since you've tested everything else. I guess that will cost a pretty penny.

[LeeT5]

Hi all. Got a customer at work with an odd issue. The brake lights on his 05 V50 are on all the time, even when the vehicle is locked up !. It's not the brake switch as the problem remains even when it's unplugged, the fault also remains when various rear lights are unplugged as well as the tailgate loom. I'm thinking the fault may be down to the CEM (fusebox) as a wiring diagram shows the CEM taking a signal from the brake light switch then 3 separate feeds from 3 separate multiplugs feeding the 3 brake lights. Anybody had any similar problems like this ?

The CEM's in V50's are well known for failing as they are in the Focus's too!

If you unplug the CEM connectors in the footwell (all of them, including the one's on top) does the fault clear itself, until you next depress the foot pedal?