Hi all,

So the car tells me to check the rear lights every time I apply the brakes. With the help of my lovely assistant, we find that both brake light and well as the chmsl work every time the pedal is pressed. Nothing seems out of line....

A search on here indicates the opposite, no brake lights when pedal pressed, pointing to the security module. By the way, locking and unlocking the car flashes the turn indicators.

Any recommendations on where to start? I haven't pulled anything apart yet....

Thanks in advance,

 

I just repaired a 2000 XK8 today with the exact fault.
It turned out that the left rear side light bulb was 'inop' (burnt-out).

The right brake light bulb worked but was a 'double-filament' type bulb in the single filament socket causing the fault.
It lit but was the incorrect bulb.

I also repaired an X308 last week with a 'burnt' contact (earth) in the tail lamp bulb holder for the harness connector. I replaced the bulb holder with a good used part I had and cured the 'CHECK REAR LIGHTS' fault.

All the bulbs not only need to work but must have the correct current draw to keep the bulb fail circuits HAPPY.

Be aware that some people 'wire-around' the factory circuits to get the lights to work.

People tie the HMSL to the tail stop lamps because the SLCM semiconductors fail.
The lights work but the SLCM 'thinks' the bulbs failed.

Many reasons for the fault so do some diagnosis with the electrical guide at hand.

bob gauff

 

Thanks, I'll run each of those suggestions down. I did notice the running light on the drivers side was a dual filament bulb...they probably have the wrong bulbs in there...

Thanks again,

 

A dual filament bulb needs to be in the dual socket.
The problem is when the wrong bulb is installed in a socket.

Look at BOTH the bulb and the socket and maybe even compare both sides.

Some single filament bulbs are 5 watt and some are 21 watt in the push and twist sockets.

bob gauff

 

perhaps bob g. who is certainly more knowledgeable than i, can comment on this...in the sense that the rear break light message seems to be more often associated with either a rear side (driver) or rear side (passenger) light failure.

in tracking this problem over some time most members seem to wind up having to remove/replace bulbs or bulb housings to fix/remove the message.less likely rear/back break lights or even rear window break light.Is this your experience bob?

soon after i purchased my 2000xj8L, I noticed i would get the rear break light message-however, it was intermittent. i focused on the window break light assembly as it was loose. i would re-assemble /affix and think that the problem was solved. it wasn't. it wound up being my passenger rear side bulb,which was not making full contact (perhaps loose) when i went up a hill especially. i did not have to change the bulb,at least not yet. the message has not re-appeared in the last six months or so....

 

I had a 21w/12w brake light bulb (instead of 21w/5w) and that was that was what caused the brake light fail message / light. The lights all worked, but that bulb got hot.