bas esp malfunction

[Glenn Smith]

Yesterday the BAS ESP malfunction light came on, goes off if you restart, has come on twice so far, car is w202 c230k, is there a favourite cause, have done the reset with battery disconnected, and steering lock to lock.

cheers

 

[fuzzer]

its normally the Brake light switch.

 

[miro]

Yesterday the BAS ESP malfunction light came on, goes off if you restart, has come on twice so far, car is w202 c230k, is there a favourite cause, have done the reset with battery disconnected, and steering lock to lock.

cheers

I don't know who started the "disconnect the battery to fix it" fad but it can cost you several thousand pounds to un-fix it.

NEVER disconnect the battery unless the situation absolutely calls for it.

 

[Glenn Smith]

I don't know who started the "disconnect the battery to fix it" fad but it can cost you several thousand pounds to un-fix it.

NEVER disconnect the battery unless the situation absolutely calls for it.

Why?

 

[Glenn Smith]

its normally the Brake light switch.

Thanks for that, would this not also bring the ABS malfunction light on?

 

[fuzzer]

Thanks for that, would this not also bring the ABS malfunction light on?

when it happened to me , just the esp/bas light came on.

in regards to miros disconnect the battery thing ..

you can cook your cars Sam's and ECU by disconnecting and reconnecting the battery.

 

[miro]

Why?

Known incidents from random battery disconnection
--------------------------------------------------
Rear SAM damage
Front SAM damage
Cluster damage
Engine control unit damage
Error messages in cluster
Braking system errors

These systems are not fragile in any way but there is nothing in the owners manual stating it should be done.

 

[Glenn Smith]

Known incidents from random battery disconnection
--------------------------------------------------
Rear SAM damage
Front SAM damage
Cluster damage
Engine control unit damage
Error messages in cluster
Braking system errors

These systems are not fragile in any way but there is nothing in the owners manual stating it should be done.

I think you are referring to battery disconnection with ignition on or engine running, so long as the battery is removed correctly I doubt whether any damage would be done (if not i've had 25yrs of luck) only problems i've come accross are;

Jump starting incorrectly
low battery voltage
incorrect connection
boost starting
creating short circuits

Don't we all turn our computers off to clear sporadic faults?

 

[normanr]

What Miro says does apply to some Mercs but my handbook says QUOTE.

Diconnecting the battery
Do not disconnect the terminal clamps from the battery while the engine is running.This could damage electronic equipment (for example the alternator beyond repair).
Switch off all electrical consumers.
Disconnect the negative terminal first,then positive.

Reconnecting the battery
All electrical consumers must be switched off
connect the positive terminal first,then the negative.
Make sure that the terminal clamps are not accidentally confused.
reset the side windows,sliding/tilting sunroof and the electronic stability programme once the battery has been reconnected.

Note.
Disconnect the ventilation hose before removing the battery.Connect the ventilation hose to the battery after installing it.

This is the wording in my Mercedes supplied hand book that came with the car.

Before you disconnect your battery you should go to your hand book or search the net if you don't have one because Miro is correct to a certain extent for some models that if you disconnect your battery you will fry some of your electronics.

With these type of Mercs you even have to have the battery changed by somebody with the proper gear if it needs replacing,hope this helps
Norman

 

[Glenn Smith]

What Miro says does apply to some Mercs but my handbook says QUOTE.

Diconnecting the battery
Do not disconnect the terminal clamps from the battery while the engine is running.This could damage electronic equipment (for example the alternator beyond repair).
Switch off all electrical consumers.
Disconnect the negative terminal first,then positive.

Reconnecting the battery
All electrical consumers must be switched off
connect the positive terminal first,then the negative.
Make sure that the terminal clamps are not accidentally confused.
reset the side windows,sliding/tilting sunroof and the electronic stability programme once the battery has been reconnected.

Note.
Disconnect the ventilation hose before removing the battery.Connect the ventilation hose to the battery after installing it.

This is the wording in my Mercedes supplied hand book that came with the car.

Before you disconnect your battery you should go to your hand book or search the net if you don't have one because Miro is correct to a certain extent that if you disconnect your battery you will fry some of your electronics.

With these type of Mercs you even have to have the battery changed by somebody with the proper gear if it needs replacing,hope this helps
Norman

I am a service technician, and have been involved with building and repairing specialist vehicles for 24yrs, you are absolutely right as i said disconnecting correctly is the key. any way i think my fault does lie with the brake switch as suggested, it has only occurred in heavy traffic and is an auto, it would make sense for the switch to go high resistance whilst in heavy use. I think i'll change it, or maybe take apart and fix it.

 

[Glenn Smith]

well i have replaced the switch (£8.48 genuine part) i've taken the old one apart and found the main contacts to be burnt, we'll wait and see if the fault has gone. I'm still a little confused by the previous remarks on battery disconnection and re-connection any body actually experienced problem after disconnection or replacement (other than having to reset windows and steering etc.)