Hi all,

The cruise control in my 1998 X308 is not working. I've tried everything that I can think of with no success.
When pushing the brake pedal, there's a failed brake light warning in the instrument cluster.
All brake light bulbs are good, including the third brake light bulbs.
I've changed the brake light switch on the brake pedal, still no success.
There are no vacume leaks.
Is there anything else which I need to check?

Looking forward to hearing from you all.

Regards ~ Denzil Sequeira

 

Sounds like the SLCM output semi-conductor has failed to the Brake Light.

Any fault will likely disable the speed control.

 

Okay. I do have a spare SLCM. Will swap it tomorrow and check if it makes a difference.
Question. If the semi conditioner controlling the brake lights has failed, wouldn't it mean that the brake lights dont work at all. My brake lights do work.
Thanks ~ Denzil

 

There are TWO micro-switches in the brake sw assy. Maybe the SPEED CONTROL switch failed and the LIGHT switch is OK?

 

I tried changing the sw assy and before putting in the new one, checked both the switches : )

 

So I'm back, swapped the security module but still the same fault (rear lights not working when you step on the brake).

Help !!!!!
: )

 

You need to check the EARTH (ground) wires to the rear lamp assys.

Many times I have had to install an alternate/parallel black earth wire.
I always make it detachable so the lamp holder can be removed if needed.
Some people make a permanent ground and you have to cut the wire to get it completely detached from the car.