ASL Warning Light 500SL '91 - How do I fix...

[B4MMY]

My ASR warning light came on after I steam cleaned my engine. This has reduced the bhp and made the accellerator very heavy. I have disconnected the battery for a short time twice, to no effect. Can anyone help me? I don't have a huge load of cash so any advice would be very gratefully received. Thanks


(Edited by B4MMY at 12:10 pm on Oct. 28, 2002)


(Edited by B4MMY at 12:11 pm on Oct. 28, 2002)

 

[Arnie]

ASL Warning Light 500SL '91

Sounds like you got water into somewhere you shouldn't! Check to see if you've dislodged any connectors with the water jet and try some WD40 to displace any water.
Also, check the fuses. These are just general things, but someone with more experience of a '91 Sl may be of more help.

 

[Andy]

ASL Warning Light 500SL '91

Hi Chris,

So disconnecting the battery did not work huh!

You will have to get the fault codes read. So you have some direction as to what is happening.

Regards

Andy @ www.mercedesservicing.com

 

[B4MMY]

ASL Warning Light 500SL '91

Thanks for your comments. No, the battery thing didn't work, and spraying the exposed bits with WD40 this morning had no effect either. Do you think this will be an expensive fix? Can't believe this has happened, I've only done 100 miles in it, bought the car off a friend and am sure he wouldn't try a fast one on me...

 

[Arnie]

ASL Warning Light 500SL '91

Here is what I have found on ASR

"1971-1986

The foundations of ESP® were laid by Mercedes-Benz back in the 70s and 80s when the company developed the Anti-lock Braking System (ABS, "Antiblockiersystem"). Based on ABS technology Mercedes-Benz developed Acceleration Skid Control (ASR, "Antischlupfregelung"). ASR intervened in both the brake system and the engine to regulate the play between the longitudinal forces at the tyre and the road surface. This system operated not only during braking (ABS) but for the first time also when accelerating. ASR made its debut 1981 in the W126 S-class. "

http://www.prismtk.de/docs/info/kfz/pkw_16.html


If you are loosing engine power, it seems that the ASR system may be cutting-in permanently. This is a development of ABS and it could be that you have upset a wheel sensor or something like that. Or perhaps something has happened witht the car's ECU (water ingress?).

Whatever. There could be many causes and so, as Andy says, you will need to get your car plugged into a diagnostics unit (dealer may give free diagosis?) to see what exactly has gone wrong.

(If it's water ingress into the ECU, (from experience) try dying it out before getting a new one- they are usually quite robust.)

 

[B4MMY]

ASL Warning Light 500SL '91

Sorry to sound thick Arnie, but where is the ECU and how do I dry it out?

 

[B4MMY]

ASL Warning Light 500SL '91

OK just one last time, and I'll leave this one alone.

When I switch the engine on and rev to over 2000 the ASR light is off. When the revs drop below 1000 the light comes on and stays on.

As I said in an earlier post, does anyone know where the ECU is, so I can pull it out, look at it, or put a hairdryer on it?

Thanks again everyone.

 

[Arnie]

ASL Warning Light 500SL '91

I'm afraid I don't know where it is on an SL. It could be somewhere on the rear engine bulkhead or it could be behind the passenger dash panel, inside the car (in which case it probably didn't get wet).

I think you should do a diagnostics check and then if it's the engine controller itself at fault, investigate further.

It could still be a connection or sensor fault and barking up the wrong tree without all the data cn be time-consuming, if not expensive.

I had a similar problem on a BMW 3 series, where the ECU, being in a recess in the rear engine blulkhead got flooded with rain water when the rubber drain-hose for that area, which included the wiper and ventilaltion intake, became blocked with leaves and debris. Dried out the ECU board and coated with an electronics "tropicalisation" varnish and good as (better than)  new.

 

[Jim_C180]

ASL Warning Light 500SL '91

It might be worth checking the alternator and battery. I beleive the ASR light will come on in a low voltage situation. Revving the engine will increase output from the alternator and put the light out.

Could be that you got water in the alternator or the washing has upset some connections to the battery or earthing points.

 

[Andy]

ASL Warning Light 500SL '91

Hi

Nice thought Jimmy, but shouldn't the ABS light come on as well. Soon as the voltage drops to or below 9v then the ABS stops working and puts the light on.

Regards

Andy @ www.mercedesservicing.com