98 SL60AMG-BAS/ASR light stays on

[tsmat]

I have a 1998 SL60 AMG which has been stored over the winter and the battery ran itself flat - after charging the battery the engine starts but hunts badly, the throttle pedal has no effect on engine revs and the BAS/ASR light stays on. I think the problem is probably to do with the ASR becoming unable to determine direction because the battery went flat but I do not know how to reset it. I have tried turning the steering from lock to lock but made no difference - any ideas or help much appreciated.

 

[stats007]

Brake light switch would be the first port of call - there is a pedal value sensor for the throttle as well - ASR is linked with EBR and the acceleration control module.

 

[tsmat]

Thanks for the response - I do not have a manual, could you please tell me where the switch and sensors you mention are located.

Many thanks

 

[television]

The brake light switch over the brake pedal is the biggest reason for the ESR/BAS to stay on, about £9 .

This may not be the problem, but has to be the first por of call.

Malcolm

 

[stats007]

You won't find a (workshop) manual for your car. Mercedes offer the WIS and EPC systems which are useful - there is an old EPC hosted in Russia that can provide you with parts diagrams etc - though part numbers generally are now out of date.

The brake light switch is number 128 on this diagram:

Old part number is A0005459909 - superceeded by A0015450109 - £10 from the dealer.

You may want to check the battery out as a matter of course - like most modern cars R129s can be particularly sensitive to a poor supply.

If the battery was flat then you will need to reset the BAS system and resync the windows as described in your handbook.

Late model SL60s are very rare - some photos would be good if you have the time!

 

[jibcl500]

You need a new battery, the ECU's on the car are not getting the voltage they need to function, new battery will solve the problem.
jib

 

[tsmat]

Many thanks for the replies - I will work through the suggestions tomorrow and let you know the outcome.
I have checked in my handbook, which says how to reset the windows but not the BAS - just says if light stays on refer to Merc Main dealer !!
I will post some photos asap

Regards

tsmat

 

[television]

Many thanks for the replies - I will work through the suggestions tomorrow and let you know the outcome.
I have checked in my handbook, which says how to reset the windows but not the BAS - just says if light stays on refer to Merc Main dealer !!
I will post some photos asap

Regards

tsmat

I over looked your battery,once they have been flat for a while,they seldom get up to the full 12 volts again,this can give the fault that you have as Jib said

Malcolm

 

[stats007]

Alternator voltage is 14V - so a bit different if you're running the engine. BAS is reset by turning the steering wheel all the way to the left and then to the right with the engine running then switch off.

 

[television]

Alternator voltage is 14V - so a bit different if you're running the engine. BAS is reset by turning the steering wheel all the way to the left and then to the right with the engine running then switch off.

If a battery cell is partly short circuit it pulls the running voltage down to below the 11.7 v min running voltage.

My SL could put the ESP on just by leaving the garage, with the new battery its never come on.

malcolm

 

[stats007]

Seems a bit silly to monitor the battery voltage if the alternator is supplying the correct voltage - after all that's what voltage regulators are for.

 

[television]

Seems a bit silly to monitor the battery voltage if the alternator is supplying the correct voltage - after all that's what voltage regulators are for.

Electrics do not work like that, the alternator only has one output, that output is feeding the car,engine and battery, regulators stop over voltage and the alternator output, yes the sensing circuit will want to charge but it cant, dont forget that the max spare volts to charge is only 2 volts.

malcolm

 

[stats007]

Well they work like that on Gensets - the battery voltage was irrelevant as once it were running it just needed continuity to operate.

 

[television]

Well they work like that on Gensets - the battery voltage was irrelevant as once it were running it just needed continuity to operate.

Gen set are something else, if it had an output of 12volt then that would not charge a battery.

Malcolm

 

[stats007]

I still don't see the relevance. If the alternator is supplying 14v then the battery can charge - it also provides power directly - not through the battery - so once the car is running it should be irrelevant whether the battery can hold a charge or not.

 

[television]

if a battery is short circuit on one cell or more the voltage must fall due to the current flowing within that short and the drop in the internal resistance of the battery as a whole.

Yes with shear power can can increase what goes into the battery,my big old Crypton was a charger come starter, and it could charge up to 100 amps.

Once you get the voltage beyond 15 -16 volt the battery will start to get hot due to the current flowing, eventually the battery will boil, due to the internal welding of the short that will drop the voltage further increasing the current still further to the point where it will explode.

Malcolm

 

[television]

I still don't see the relevance. If the alternator is supplying 14v then the battery can charge - it also provides power directly - not through the battery - so once the car is running it should be irrelevant whether the battery can hold a charge or not.

No, the car runs on the alternator 30amps,consumers 30 amp so a 80 amp alternator would have 20 amp spare for the battery. Alternator cannot and are not designed to charge flat batteries and if you keep trying to you will blow the reg pack

If you take the battery off of a running car,the bulbs will blow as can the ECUs as the battery holds the voltage at the max level of 13.8 volt for the max spare current available. If the internal resistance of the battery drops,so will the voltage (Ω law governs this)

malcolm

 

[television]

On all rechargable batteries the voltage drops to the point where they are Short circuit, car batteries do not behave quite as bad but shorts between the plate do happen, in the old day we used to wash them out and re fill often short lived as it was the plates (lead) that shed particles that could build up till a short circuit was present.

Malcolm

 

[jibcl500]

Last year I had problems with the ESP and ABS lights on until one day I couldnt move the car because the ETA was in limp home mode. The battery was shot, new battery fitted and the lights still came on on the dash but on a second restart all was fine and has been for the last year.
I will give Malcolm £5.00 to give to children in need if Im right and £10 to the same if Im wrong.
Just remember MB are a complex motor, most electrical faults I tend find are down to failing batteries, range rover are the same.

jib

 

[stats007]

I hear what you're saying - the battery acts as a regulator during normal use - so is in turn an essential component.