BAS ASR light

[GarethM]

Ok after queueing through the pay as you drive car park otherwise known as longleat safari park ! grrr my BAS/ASR light has switched itself on and refuses to go out on a simple ign on, ign off.

The crusie control has also stopped working - but was fine for the jouney down there. Im guessing that the hammering the brakes, stop, start, stop, start around longleat has seen fit to cause some form of sensor to give up the ghost ?

Reading around http://www.mbclub.co.uk/forums/showthread.php?t=27473&page=2&highlight=BAS+light

it seems that it could be the brake light switch or an ABS sensor. Ive checked my brake lights and they work fine ( So assume the switch is fine ? ). Im looking for clarification if its a multiway switch and if they fail only half dies but the light still work ? Or if there is a way to tell which ABS sensor may have died ? ( If it is an ABS sensor - why does the ABS light not come on ! )

Or if anyone has anything else i could try ! Please help ........ ( I dont want to have to go to a stealer )

Oh .. Also .. possibly unrelated - i turned the aircon EC off and it would only blow hot air ! i think ive got gremelins ! )

Thanks

G

 

[Aletank]

If you have it - Does your automatic door locking still lock at 5mph?, If thats stopped working its probably the ABS Speed Sensor

 

[racall]

I had the same problem.My brake lights worked fine.After changing the brake light switch everything was O/K.

 

[Mercedes cozy]

Bit of advice. In a case like this I would check the really basic things like fuses. I'm always in favour of checking basic things first as most of the things that are faulty are always something small and silly.

Check your fuses first. Post your results. Also check your manual what it states about the lights coming on.

 

[BenzComander]

Brake light switch for the BAS/ASR problem. Takes ten minutes to change at max and is cheap as chips from the stealer!!

Aircon recap, light on no aircon, light off should blow icy cold at lowest settings on temp gauges.

HTH

 

[GarethM]

Thanks for you replys guys. Ive found somthing else .... When I turn the ingnition on with the brake on, the BAS/ESR light does no light up, it only lights once i release the brake light.

Aletank - I dont think i have auto door lock ( 1998 W208 )
racall - Excellent thats what i was hoping
Mercedes cozy - Checked the manual first, simply states an error with BAS or ESR and if voltage drops below 10v. All fuses fine.
BenzComander - Yup merc AC is back to front ( imho anyway )

Ill get a brake light switch tommorow... Has anyone brought one from any other source - ie not a dealer ? Also if it is the switch it should be possible to test ?

Cheers

G

 

[DrNick]

An easy test is to check the battery voltage, although if the car starts OK then that probably isn't the issue!
(I'm thinking of the voltage dropping below 10V)

Thanks for you replys guys. Ive found somthing else .... When I turn the ingnition on with the brake on, the BAS/ESR light does no light up, it only lights once i release the brake light.

Aletank - I dont think i have auto door lock ( 1998 W208 )
racall - Excellent thats what i was hoping
Mercedes cozy - Checked the manual first, simply states an error with BAS or ESR and if voltage drops below 10v. All fuses fine.
BenzComander - Yup merc AC is back to front ( imho anyway )

Ill get a brake light switch tommorow... Has anyone brought one from any other source - ie not a dealer ? Also if it is the switch it should be possible to test ?

Cheers

G

 

[GarethM]

Ok
Brake switch replaced - and all is well woohooooo

For those with a similar problem in the future. There are 2 sets of contacts on normally open ( big set ) and one normally closed ( small set ) and they should alternate when the switch is pressed. On my switch the smaller set of contacts was perminatley open circuit no matter what position the switch was in. Hope that helps someone ........

Thanks for everyones help.

G

 

[GRAV888]

You should have auto door lock.
IIRC, you can turn it on and off by pressing and holding the door open / lock switch on the dash until it flashes.