Are these the deadly Brake Switch symptoms

[cobra427]

hi all,

I have a 1999 Auto C200 Sport (yup, as sporty as chipped Zimmer!).

Anyway, the other day the yellow ASR/BAS light came on and stayed on and the cruise control stopped working.

A restart of the engine the light comes on.... BUT...
If I press the brake pedal when i start the engine then the BAS light doesn't light up and the cruise works fine (until the light comes on again maybe a few mins later)

Now today a bulb warning light also came on with no apparent bulb failure... could that also be a symptom of a wonky brake switch?

 

[pascal]

Could be. But I would check the pressures in my tyres first. low pressure in one tyre can cause non-working cruise and/or illumination of Asr/esp lamp.

It is also posible that is a faulty wheel sensor, or brake light switch

 

[simon morgan]

could low tyre pressures also cause the problem I have been having with the ABS light? See "Electrics Mayhem".

 

[jberks]

I've never had this myself but if you start getting unrelated failures, it seems that the common culprit is the OVP relay. I don't know much more than that but others do.

 

[cobra427]

I checked out the lights and yup! i forgot about the number plate one... anyway that solves the light warning lamp. BUT I've still got the BAS/ASR warning...(and tyres are fine)

Given that the BAS light goes out if I start up with the brake pedal pressed then it seems to be likely related to the brake switch

- HOWEVER -

is the other culprit (the wheel speed sensor) mounted close to the brake pads ?? If so I guess pressing the pedal at start up may generate enough movement to magically 'cure' the BAS problem (for whatever reason)