Continuing ASD Frustration! 300CE C124

[derin100]

Having always had an empty ASD reservoir on my 124 300CE ever since I got the car I decided, in my wisdom, that as the last job in a very long renovation I would fill the reservoir and see what happens.

Firstly and predictably there's a leak! It's from one of the rigid pipes that goes into the pump under the car.

When I took the two pipes off the reservoir in the engine bay the fluid was being pumped out at a fair rate of knots so at least I know the pump is working!

I've not had time to get a new pipe (or probably more likely one made up) and so my local garage just tried to temporarily seal the small hole in the pipe with some of that "Liquid Metal" type stuff. Well, that hasn't worked because it's still leaking...but not massively so.

However, the problem now is that the "ASD" light illuminates on the dash.

So, after a bit of reading on the internet here's what I've tried so far:

1) I ran the recommended diagnostic test by taking a wire and inserting it into port 5 on the diagnostic port, grounding it and counting the number of flashes of the ASD tell-tale.

It flashes 8 times which is supposed to mean either a brake-light switch fault or a "magnetic switch" (I don't know what the latter is?)

So, I've just bought a brand new brake-light switch and still exactly the same...8 flashes!

2) I've also just tried another (known good) OVP and still exactly the same 8 flashes!



What do to next?

Will the fact that it's still got a very small leak from the pipe be causing the ASD tell-tale to illuminate?

But why is it still giving me the same 8 flash error?

Any advice thoughts greatly appreciated.

Thanks in advance.

 

[grober]

Try this thread- very informative. Must ASD Lamp light up? - Page 2 - Mercedes-Benz Forum You may just have to bleed the system.[ bleed nipple on the diff ] It's also possible the hydraulic solenoid is faulty [ the other possible explanation of fault 8 flashes] its similar to the W124's suspension self levelling system in that it has a pressurised sphere where there is a diaphragm separating the hydraulic fluid and nitrogen gas- this can leak out or the diaphragm rupture. Other problem can be electrical with a faulty or corroded relay.

 

[derin100]

Thanks Graeme.

From a reminder on another forum, I realised that after installing the new brake-light switch and swapping OVPs I hadn't done the fault clearing procedure of holding the wire grounded for greater than 10 secs.

I've just done that and left the car running for 5 mins and the ASD tell-tale hasn't come on again.

I know not to count my chickens too soon...but this might possibly have done it!

Now, I still need to get some piping to repair that leaking pipe!

Thanks again.

P.S when you try to read through all that stuff in the link above you feel like just doing away with ASD completely!