2003 BMW 330cic
When I press the brake pedal it not only disengages the cruise control, but it shuts it off completely. In order to turn the cruise back on I either have to stop the car and crank it without touching the brake pedal; or I have to be driving down the road, shift into neutral, turn the car off, turn the car back on, shift back into drive, accelerate, and then turn the cruise control back on. If I press the brake pedal during this procedure it automatically turns the cruise control off. Obviously it is not safe to do this.
Also, the convertible top will not go down. The light next to the switch turns yellow. I think this is associated with the brake problem since you have to have the brake pedal pressed down in order to put the roof down.
Is there a sensor of some kind that may have gone bad?
There is one more rather important issue that I failed to mention, previously. At any time that I press the brake pedal...whether I am in park, at a stop sign, or traveling down the road...it disengages the accelerator. The engine drops down to idle and as long as you have your foot on the brake it will not accelerate. Have no idea what that's all about!
Last edited by Jim P; 01-21-2019 at 02:25 PM.
The roof and the CC are unrelated components. If any one WINDOW does not roll down, the roof will not either. And you never need to have the brake depressed for the roof to work.
I would scan the car and check for faults, the top looks for a lot of safety signals before the top will work
The brake light switch is common to the soft top, cruise control and brakes. The switch has two outputs, one to the brake lights and DME and the other is a test switch that goes to the DME. The test switch side tends to break causing soft top and cruise control to stop working. Look for brake light error codes when you do the scan.
1999 2.8L Z3 Roadster,
2000 3.0L Z3 Roadster,
There is only one thing more pleasurable than working on a Z3, that's driving it top down on a fine day.
Thanks for the advice. I replaced the brake switch and it made no difference. I did identify the problem with the roof...it was not associated with the brake. So, if the problem with the cruise control and acceleration do not come from the brake switch...what could the problem be?
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