Upper rear brake lights not working

AMCG · Apr 23rd, 2023, 18:41

Both right and left high level brake lights stopped working simultaneously. Can’t find a fuse for them in diagrams. Only other light out is the interior courtesy light on the tailgate door. I’ve replaced the bulb. Any ideas folks?

Moose Test · Apr 23rd, 2023, 19:55

The brake lights don't have a separate fuse, they are fed directly from the main supply to the Rear Electronic Module. It's fused on position one of the cargo area fuse box (11E/1 on the diagram, located near the battery under the cargo floor).

However, I think it unlikely that will have blown as it's rated at 60A and that would be one huge short circuit. If it *has* failed, then the REM is out in its entirety and you'll have other problems, including with the rear door locks, reversing light and rear wiper.

It's worth removing the light fittings (and the interior trim, if necessary) to check the connectivity to both, including earths but seeing as they're on opposing sides of the vehicle and won't have much cable run in common, I'd be inclined to think there's a more generic cause - a failed relay/transistor in the REM. I am assuming that you've already checked the bulbs.

TruckbusUK · Apr 23rd, 2023, 20:59

Upper brake lights ? .... do you mean the single one in the tailgate?
You don't say what model or age of XC90 you have but the mk1 XC90 doesn't have the upper section lit (not sure about the LED version, but I thought they were only marker lights.), the only brake light is on the main LHS and RHS cluster.

Hope it helps

idainc · May 8th, 2023, 23:19

Are you getting a "check stop lamp" message ?

Apr 23rd, 2023, 18:41	#1
AMCG New Member Last Online: Apr 23rd, 2023 18:44 Join Date: Apr 2023 Location: Sheffield	Upper rear brake lights not working Both right and left high level brake lights stopped working simultaneously. Can’t find a fuse for them in diagrams. Only other light out is the interior courtesy light on the tailgate door. I’ve replaced the bulb. Any ideas folks?

Apr 23rd, 2023, 19:55	#2
Moose Test Master Member Last Online: Apr 26th, 2024 14:25 Join Date: Sep 2017 Location: Norfolk	The brake lights don't have a separate fuse, they are fed directly from the main supply to the Rear Electronic Module. It's fused on position one of the cargo area fuse box (11E/1 on the diagram, located near the battery under the cargo floor). However, I think it unlikely that will have blown as it's rated at 60A and that would be one huge short circuit. If it has failed, then the REM is out in its entirety and you'll have other problems, including with the rear door locks, reversing light and rear wiper. It's worth removing the light fittings (and the interior trim, if necessary) to check the connectivity to both, including earths but seeing as they're on opposing sides of the vehicle and won't have much cable run in common, I'd be inclined to think there's a more generic cause - a failed relay/transistor in the REM. I am assuming that you've already checked the bulbs. __________________ 2007 XC90 V8 Sport

Apr 23rd, 2023, 20:59	#3
TruckbusUK Petrolhead+Lots of Diesel Last Online: Yesterday 16:01 Join Date: Aug 2008 Location: Glasgow	Upper brake lights ? .... do you mean the single one in the tailgate? You don't say what model or age of XC90 you have but the mk1 XC90 doesn't have the upper section lit (not sure about the LED version, but I thought they were only marker lights.), the only brake light is on the main LHS and RHS cluster. Hope it helps __________________ BMW X3 Msport MHEV 2020MY & VW Beetle Design 1.2Tsi DSG 2014MY Previous XC90 D5 SELux Geartronic 2009MY Last edited by TruckbusUK; Apr 23rd, 2023 at 21:17.

May 8th, 2023, 23:19	#4
idainc New Member Last Online: Jun 22nd, 2023 14:25 Join Date: Dec 2015 Location: Palm Springs	Are you getting a "check stop lamp" message ?

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