Volvo Community Forum. The Forums of the Volvo Owners Club

Forum Rules Volvo Owners Club About VOC Volvo Gallery Links Volvo History Volvo Press
Go Back   Volvo Owners Club Forum > "Technical Topics" > XC90 '02'15 General

Notices

XC90 '02'15 General Forum for the P2-platform XC90 model

Information
  • VOC Members: There is no login facility using your VOC membership number or the details from page 3 of the club magazine. You need to register in the normal way
  • AOL Customers: Make sure you check the 'Remember me' check box otherwise the AOL system may log you out during the session. This is a known issue with AOL.
  • AOL, Yahoo and Plus.net users. Forum owners such as us are finding that AOL, Yahoo and Plus.net are blocking a lot of email generated from forums. This may mean your registration activation and other emails will not get to you, or they may appear in your spam mailbox

Thread Informations

Brake lights not working 🚨

Views : 250

Replies : 9

Users Viewing This Thread :  

Reply
 
Thread Tools Display Modes
Old May 2nd, 2021, 16:05   #1
Tony500
Master Member
 
Tony500's Avatar
 

Last Online: May 11th, 2021 07:10
Join Date: May 2014
Location: Glasgow
Default Brake lights not working 🚨

The two side brake lights have been intermittent the past month, on Wednesday coming back from Millport the check brake light message came on the dash and I cannot figure out what's up.... the 3rd brake light works fine, all fuses and wires are good to my knowledge.
What can it be before I take a feed from the 3rd brake light 🤔



The car is a 07 xc90
__________________
2009 V70 R-Design 2.0D SE Sport
2007 XC90 D5 SE Lux
2006 XC90 V8 Executive
Tony500 is offline   Reply With Quote
Old May 2nd, 2021, 18:23   #2
john langrick
Master Member
 

Last Online: Today 11:30
Join Date: Dec 2016
Location: Southend on sea
Default

Hi, I understand that for safety reasons the high level stop lights and the low are on separate circuits for failsafe reasons. If you short them you could start causing further problems.

I also understand that, on some models, part of the stop light circuits are on the cem rather than the rem.

However, on tracing problems on an earlier v70, I discovered my problem was with the relays, in my case the lower port and starboard lights.

I found the problem by swapping relays for those with the same part number.

You need to check the wiring diagrams to see if the relays are on the rem or cem.

My own xc90 is an earlier model so cannot compare.

I hope this helps..

John l
john langrick is offline   Reply With Quote
The Following User Says Thank You to john langrick For This Useful Post:
Old May 2nd, 2021, 23:38   #3
Tony500
Master Member
 
Tony500's Avatar
 

Last Online: May 11th, 2021 07:10
Join Date: May 2014
Location: Glasgow
Default

The relays are a part of the cem and not changeable. You can change but need to solder ect.. I'm not getting a signal from the yellow signal wire from the rem but getting a signal when it's going in. I've put a fused bridge on there for the now until I figure out what needs done
__________________
2009 V70 R-Design 2.0D SE Sport
2007 XC90 D5 SE Lux
2006 XC90 V8 Executive
Tony500 is offline   Reply With Quote
The Following User Says Thank You to Tony500 For This Useful Post:
Old May 3rd, 2021, 07:43   #4
john langrick
Master Member
 

Last Online: Today 11:30
Join Date: Dec 2016
Location: Southend on sea
Default

Just another thought..

Can you get the part number off the rem?

If you can and then look on the 'bay' you will probably be able to get the same part number unit for < 20. Not sure if it would need programming but I suspect it does not.

Hopefully others could confirm?

Again, I hope this helps.
john langrick is offline   Reply With Quote
The Following User Says Thank You to john langrick For This Useful Post:
Old May 3rd, 2021, 10:39   #5
Clan
Experienced Member
 
Clan's Avatar
 

Last Online: Today 12:29
Join Date: Jun 2007
Location: L/H side
Default

Quote:
Originally Posted by Tony500 View Post
The two side brake lights have been intermittent the past month, on Wednesday coming back from Millport the check brake light message came on the dash and I cannot figure out what's up.... the 3rd brake light works fine, all fuses and wires are good to my knowledge.
What can it be before I take a feed from the 3rd brake light 🤔



The car is a 07 xc90
It needs the brake light input signal for the REM checking on the network with VIDA
Vida will also send that signal manually so checking the REM itself , have you measured the outer brake light feeds from the REM ?

It just needs some simple diagnostics ..
__________________
My comments are only based on my opinions and vast experience .
Clan is online now   Reply With Quote
Old May 3rd, 2021, 16:21   #6
oragex
Premier Member
 
oragex's Avatar
 

Last Online: Yesterday 18:38
Join Date: Jun 2013
Location: Coldnada
Default

As mentioned by Clan look at the REM relays https://volvos60xc70xc90buyersguide.home.blog/
__________________
Several Volvo Repair Videos https://www.youtube.com/playlist?lis...ECTts0FSVSOT_c
oragex is offline   Reply With Quote
Old May 4th, 2021, 12:04   #7
Tony500
Master Member
 
Tony500's Avatar
 

Last Online: May 11th, 2021 07:10
Join Date: May 2014
Location: Glasgow
Default

Quote:
Originally Posted by Clan View Post
It needs the brake light input signal for the REM checking on the network with VIDA
Vida will also send that signal manually so checking the REM itself , have you measured the outer brake light feeds from the REM ?

It just needs some simple diagnostics ..
The yellow signal wire going into the rem is getting a feed but the yellow signal wire coming out has nothing. No fault on the dash when I've bridged the two wires with a 5amp fuse.
I've not had a chance to get visa on it yet but will later this week but my autel points to a short on the circuit so I presume the internal relay is shot?
__________________
2009 V70 R-Design 2.0D SE Sport
2007 XC90 D5 SE Lux
2006 XC90 V8 Executive
Tony500 is offline   Reply With Quote
Old May 4th, 2021, 12:22   #8
Clan
Experienced Member
 
Clan's Avatar
 

Last Online: Today 12:29
Join Date: Jun 2007
Location: L/H side
Default

Quote:
Originally Posted by Tony500 View Post
The yellow signal wire going into the rem is getting a feed but the yellow signal wire coming out has nothing. No fault on the dash when I've bridged the two wires with a 5amp fuse.
I've not had a chance to get visa on it yet but will later this week but my autel points to a short on the circuit so I presume the internal relay is shot?
Well that is a clue .. so you bridged the Green/yellow * (A18) input wire from the CEM to the two Yellow output wires (B3) with the pedal pressed and nothing happens , no voltage ?

There is a direct link through in the REM for these terminals , switching is done in the CEM .

(* = the input signal to the REM from the CEM is a Green wire with a yellow stripe ) .
__________________
My comments are only based on my opinions and vast experience .
Clan is online now   Reply With Quote
The Following User Says Thank You to Clan For This Useful Post:
Old May 4th, 2021, 16:11   #9
Tony500
Master Member
 
Tony500's Avatar
 

Last Online: May 11th, 2021 07:10
Join Date: May 2014
Location: Glasgow
Default

Quote:
Originally Posted by Clan View Post
Well that is a clue .. so you bridged the Green/yellow * (A18) input wire from the CEM to the two Yellow output wires (B3) with the pedal pressed and nothing happens , no voltage ?

There is a direct link through in the REM for these terminals , switching is done in the CEM .

(* = the input signal to the REM from the CEM is a Green wire with a yellow stripe ) .

The yellow wire coming from the cem and the yellow wire from the rem is the ones I've bridged. Never touched a green wire? So if it is a direct link you think just leave the bridge in place?
__________________
2009 V70 R-Design 2.0D SE Sport
2007 XC90 D5 SE Lux
2006 XC90 V8 Executive
Tony500 is offline   Reply With Quote
Old May 4th, 2021, 23:15   #10
Clan
Experienced Member
 
Clan's Avatar
 

Last Online: Today 12:29
Join Date: Jun 2007
Location: L/H side
Default

Quote:
Originally Posted by Tony500 View Post
The yellow wire coming from the cem and the yellow wire from the rem is the ones I've bridged. Never touched a green wire? So if it is a direct link you think just leave the bridge in place?
The diagram I looked at was a 2007 and the one from the CEM is green with a yellow stripe .

Yes the diagram indicates a solid internal REM connection between the two wires .
__________________
My comments are only based on my opinions and vast experience .
Clan is online now   Reply With Quote
The Following User Says Thank You to Clan For This Useful Post:
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 12:55.


Powered by vBulletin
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.