ABS ASC+T Light On Return Pump Troubleshooting

That's pretty much 100% evidence that it is the return pump - the other likely cause is the wheel sensors - but they would throw a code, and you don't have one for them!

As far as I remember, The ABS module checks the voltage actually at the pump - but, check Fuse 65 in the Auxiliary Relay Box - it is on LH front wing under the bonnet, right above where the ABS block is

I had issues with my pump as well. I knocked on it a couple of times with a screw driver and ever since it works again. (Knock on wood...)
It seats in an area where it gets a lot of water and dirt.
Here is a tutorial how to overhaul the ABS Block.
I actually bought one used ABS Block from an E39 for cheap (check the part number) and put it aside for the time my one gives up.
(In E38 and E39 the ABS block is located in a dry, "safe" place.)
With some hassle (bumper needs to be removed) you can change only the pump or the whole ABS Block, but then you have to get the air out of it which is a lot of hassle and needs DIS or GT1.

Cheers,
Steve

Change first the relais on the pomp I suggest, there may be a fault there....

Yes, brake fluid for the ABS system - it is all part of the brake system. Use INPA to open the valves when bleeding the brakes initially, then close all valves for the final bleed - I believe that this can be done as a procedure in DIS.

Old tread that seems to have a few questions not closed yet , and since I am wondering about the same i'm putting it back to life

Also wondering about bleeding the whole system as I did drain it all , Pentosin and brake fluid while replacing all pipes under the car.
Can this procedure be done with DIS ?

Anyone tried this before , please trow some light on the topic

Regards
Terje

Well I just tested and found out what happen

When opening the bleeder there was pressure behind even without car running , a lot of bubbles and foam came out then pressure was gone.
Started the car and continued until no bubbles and foam was present

Using a brake bleeder and pretty straight forward , guess it should be done whenever emptying the Pentosin system and filter replacement.

8er.org/forum/index.php?attachment/29600/

Very interesting, Terje...
but my question now is: is there a bleeder there on the 850CSi? Because I can't remeber of any in my 840...

Yes Danilo, it is on every 850 CSI, also on every 850 with 6speed Gearbox as standard and on every 850 with the option ASC+T.

Zitat von huldra66;124856

Old tread that seems to have a few questions not closed yet , and since I am wondering about the same i'm putting it back to life

Also wondering about bleeding the whole system as I did drain it all , Pentosin and brake fluid while replacing all pipes under the car.
Can this procedure be done with DIS ?

Anyone tried this before , please trow some light on the topic

Regards
Terje

Alles anzeigen

DIS has a special procedure to bleed the ABS block. Do you have DIS on your PC/notebook Terje?
I have to do it soon on my 850i and could probably take some screenshots if you like.

Cheers
Wolf

Zitat von wokke;125146

DIS has a special procedure to bleed the ABS block. Do you have DIS on your PC/notebook Terje?
I have to do it soon on my 850i and could probably take some screenshots if you like.

Cheers
Wolf

Yes please do some screen shot's need to learn myself

Thanks
Terje

Yes please wokke, take screenshots of the process because I've been unable to locate the ABS/ASC+T bleeding functionality in DIS. It might depend on the model of ABS module but as far as I know there are only two ASC+T modules for the M70/S70: 34 52 1 158 804 and 34 52 1 159 494 with a changeover around mid 1990. I know for certain that the first one cannot be diagnosed by DIS/INPA at all (only stomp codes) and the second one also seems to be from another era with regards to diagnostics. DIS is only able to read and clear fault codes and retrieve the "BB number" (serial or model number I guess). No other functionality is present. Same with INPA...

I think the ability to diagnose the ABS depends on the manufacturer. I'm currently having the issue on a 01/93 850CSi where the bleeder function of DIS doesn't work.
DIS reports TEVES as the manufacturer of the ABS system. I haven't yet checked if this is true or another screw up in this car packed with surpríses.
The functionality as such is on the very end of all diagnosable module (IIRC page 3) of DIS. I never found anything similar in INPA at all but admit that I also never looked for it in there.

I may get a chance to take some screenshots today. If not for sure after the Hockenheim meeting this weekend.

Oh I see... It's under "[56] ABS/ASC TESTER" instead of "[50] ANTI-LOCK BRAKING SYSTEM (ABS)". Strangely this diagnostic program (56) does not show up after performing the short test (which I usually do to get rid of modules not installed in my car) so I never noticed it. I have yet to test with the car connected so I do not yet know whether it actually works...

Now I also got curious , might have to fire up my laptop as well.
But I seemed to have bleed the brakes good now , but had to do it twice to get pedal hard as it seemed good and the got soft the first time ( assuming some air was trapped in the ABS block )

The bleeder in the engine compartment is bleeding the ASC-T block and it's pentosin coming out.

Regards
Terje