W124 ASR light comes on and car slows down...

[E280T]

Yep, but the last time I checked it was the orange ASR light that went on. As soon as I get my car back with it's new fan belt and klima compressor (which got stuck and made the belt snap) I will remove the relay and place it again properly to see if that makes a difference. Luckely, the problem happens rarely...

 

[Number_Cruncher]

I wonder if this is a wiring insulation degradation problem. The car is the right age, and a wire shorting on the electrical throttle actuator could trigger an ASR fault.

It's quite easy to check for, as it's simply a case of removing some of the outer insulation, and having a look at the wires themselves.

 

[television]

The OVP relay is the prime suspect for this as said earlier, the Austrian versions can go dry jointed, the Irish versions are better. Some replace the wiring as number cruncher

http://www.asashop.org/autoinc/july2005/techtips.cfm

http://mercedesforum.com/forum/archive/index.php/t-258.html

http://www.k6jrf.com/MB_asr.html

http://www.mbworld.org/forums/e-class-w210/200306-abs-asr-bas-problem.html

http://www.benzworld.org/forums/w202-c36-amg-c43-amg/1239591-bas-asr-problem.html

 

[kth286]

do not forget the brake light switch on ASR cars.

very cheap and simple to replace.

 

[television]

That only applies to cares with a CAN BUS David

 

[jaymanek]

ASR cars do have a throttle cable... both of my SEC's do

An ASR light on will limit the power as its detected an issue.

As Malcolm has said, first thing to change is the OVP relay. After that it gets more difficult to diagnose... The brake light switch is a valid contender but hardly ever the cause of any issue. The ASR control modules have been known to cause problems too.. rare as rocking horse poo.

 

[kth286]

this is the 104 HFM engine so no throttle cable - all electronic.

 

[television]

this is the 104 HFM engine so no throttle cable - all electronic.

Then this car will have ASR11 and the fault codes read out.

Sorry about the brake switch,,you were correct.

 

[WDB124066]

My 104 HFM Engine, fitted with ASR, has a throttle cable from the pedal to a throttle linkage assembly in the engine bay - possibly not right through to the butterfly valve though.

I had this problem with my E320 Cabriolet and it happened after my throttle cable was adjusted to take up a little bit of "slack" in the cable. A day later it went into "Limp Home Mode" a standard recovery mode in which the car will only give a fraction of the power it normally gives. To get any power out of it at all you need to press the throttle at least half way down. This mode is a planned factory programmed mode to get you home if a fault is detected in the ASR system. The fault in my system was caused by having the cable adjusted to remove all slack. Apparently mine, at least, likes to have a tiny little bit of play ie a tiny bit of pedal travel before the cable moves in it's sheath. As soon as this is adjusted out it will go into this Limp Home Mode.
I am not so sure you problem will be solved the same way as mine was because, by the sounds of it you have not had the throttle cable adjusted, but at least it may be of some help, if not to you, then to others reading this thread in time.

Regards, to all W.

 

[E280T]

****Update****

My E280T still sometimes jumps into Limp Mode with the ASR light on, but only if it has been standing for a night (or more) in the blistering Berlin cold. During this previous spring and summer it only happened once after I had left my car parked non-stop for 3 weeks, but other then that it seems to be related with cold temps or low battery voltage. Switching the engine off and back on (mainly once, sometimes twice) resolves the issue, and if the ASR light doesn't come on within the first 3 minutes after starting the engine it doesn't come on regardless how long the journey takes or how hot the engine becomes...

Next week I will remove the OVP Relay (located behind the battery?) and clean it out. The following step after that would be to replace the Relay itself and see what that does.

May take a while for the update since the problem doesn't occur on a daily base.

Cheers!