Intermittent fault

[didgit]

hi everybody
recently my 98 C200 has been giving me some bother, the dash light for the ASR BAS keeps coming on, this happened last year also but went away on its own, this seems to happen when the cars been parked for a day or so in bad weather, ie raining. when i turn the ignition off the light goes out and stays out on restarting the engine, is this common, could it be a damp problem, any ieas and help appriciated.

[The Jackal]

I have a 97 C180, just puchased. The same thing is happening on mine as well - Its only just had a full MB service, so Im guessing its just an electrical fault, so am leaving it until next service. Scant consolation, but at least we're not alone with this issue! As with your message - is this common on the c-Class.....Thanks

[C240Sport97]

is your cruise control working when the BAS/ASR light is on? if so, then it's the brake switch, located in the big panel just under the steering wheel

[didgit]

been away for a while will try cruise next time it happens
thanks for the help

[silverarrow]

go for brake light switch if the plunger sticks then fault will be on display only 5 mins to chage and £10 part

[Steve_Perry]

Another point to bear in mind...


I remember reading in the hand book "If the electrical voltage drops below 10 volts, the malfunction indicator lamp will also light up in the instrument cluster and the Brake Assist System (BAS) will be de-activated."

S.

[Biggles]

I have just had exactly the same on my 1999 C200, I tested the cruise control, this was not working, however, the fault WAS the brake switch, so I would try that first next time, worth £10 to save £100+ which is what mine cost :eek:

[rtayal]

I have a 97 C180, just puchased. The same thing is happening on mine as well - Its only just had a full MB service, so Im guessing its just an electrical fault, so am leaving it until next service. Scant consolation, but at least we're not alone with this issue! As with your message - is this common on the c-Class.....Thanks

heay did u checked if the cruise control works when ABS light is ON. Did u found the remedy to fix it... I have got the same problem today...

[Paul Grainger]

If it isn't the brake switch then check the connections to the wheel motion sensors. these can get cruddy and give the same symptoms.

Paul G

[sym]

If it isn't the brake switch then check the connections to the wheel motion sensors. these can get cruddy and give the same symptoms.

Paul G

Where do you find these, Paul ?

[BDE1V]

I recently came out of the shower after a game of foota to find my teenage son sitting in the Drivers seat of my CLK320
On switching on the Ignition the ASR / BAS Failure light coame on.

My immediate reaction was to blame my son & this was possibly the case.

I managed to trace the fault to the Brake Switch located behind the Drivers Front Cowling just up from the Brake Pedal. ( you'll need to unscrew 4 Philips Screws & a Quarter turn screw to drop the cowling down.

I removed my switch & stripped it down to find the contacts on the 2 smaller switch contacts broken in the bottom of the switch housing.

A tip if you get this fault and have a Multimeter Handy.

To determine if your Brake switch is faulty & possibly causing this fault,

1. Leave the switch in position & pull off the two Plugs attached to tit's rear.

2. With the Pedal at rest the smaller 2 contacts should be made, & should read Zero Ohms when measured with a Multimeter on the Ohms range.

3. the two larger contacts should be open circuit at this point.

Now push the brake pedal... The two larger contacts should read zero or low resistance & the smaller contacts should now be open circuit.

If this isn't the case then you'll need a new switch ( About 11 pounds from the dealer).

If the switch is ok then you'll need to look else where.
Regards
BDE1Vhttp://www.mbclub.co.uk/forums/images/smilies/smile.gif

[Geoff2]

Just had the very same thing on my E300TD. New brake switch 5 minutes fitted. Fault shows up with the diagnostic tool.