Mercedes CLK 208 ABS, BAS AND ASR lights on problem

[PJ57]

The ABS, BAS AND AS warning lights have come on my Mercedes CLK 320 convertible a 1999 W208 model. They were intermittent at first and now on all the time. I have done the quick fix of steering wheel calibration and break light switch replacement. I took it to my local garage who I do trust but he was a bit vague (Maybe he has not got a star Mercedes specific tester?) but thought it could be the ABS ECU module and the not a ABS sensor which I was hoping it would be at the cost of about £700 probably more than the car is worth lol. The advice I need is should I just get a second hand ABS ECU and fit it myself as it does not look a hard job and the unit is inexpensive second hand and then replace the pump if that does not fix the problem. I am worried that the replaced ECU will need resetting by a STAR Diagnostic tester although some you tube videos seem to think you do not have too. If I can fix the car I will trading it for an SL so wondering whether the tester will be a good investment for the future. Any advice appreciated.

 

[John Laidlaw]

Star is quite expensive, you can have a LOT of sessions at your local trusted Indy before reaching break even so probably not worth while. An Indy will charge c£60 a session.
You may want to consider what a fair number of us have on here, the icarsoft- I have the i980 which IIRC was £100/£120 , there is an MB2 version I've heard folks on here has more functionality. Ultimately it wont do everything Star will but it will be useful to learning what your car is doing, especially if you're going for the SL (even more so if its a 500 youre thinking of).
On your current issue, you may well be advised to find someone with Star to check it out lest you splash out on parts which may not be the problem...

 

[mercedes13156]

If it's a W208, then it will probably have the reluctor ring cast into the back of the hubs. My two previous C Classes had this and on both I had much the same problems as you are describing. Everything looks like it's working, and reads ok, but you've got no cruise, ABS, BAS or ESP. If that's the case then the only thing left (and not monitored by STAR or iCarsoft etc.) is the reluctors. Take the hubs off and use a wire wheel on a drill to clean them up. You may also find that your backplates have rusted away and the muck in the grooves is what's left of the backplates.

Hope this helps.

 

[Pathfinder]

On both my 1999 and 2000 C class, the reluctor rings on the front were incorporated inside the hub oil seals. They are not visible to the eye, as they are moulded into the rubber. I had all your above symtoms a few times. Only way to rectify was to replace both front hub seals. If your set up is similar, this could be the problem. If so, new seals have to be gently pressed in, if you tap or hammer them with a mallet, they will fail again.

 

[PJ57]

Thanks guys for all your advice and the reluctor rings are an eye opener I need to do more research. Have booked the car into a indi garage to see what they can tell me
Thanks again
Phill

 

[mercedes13156]

My fix on the current car was to tap the seals gently into the hub with a piece of plywood over them to prevent damage from the hammer. Only put them flush to the back of the hub. Don't push them in until they stop. Worked first time for me.

 

[Pathfinder]

Better to press them into position in a vice or press, using an old cd disc as a soft face between the seal and the vice jaw/ press piston.

 

[mercedes13156]

The seals are very soft and the metal rings will distort if you whack them in. I pushed then in about 2mm by hand then used an offcut piece of plywood and rubber mallet to tap them in very gently.

Whatever method you use, be careful.

 

[PJ57]

Back again
Had the car diagnosed with a faulty rear near side abs sensor. Thinking of testing the sensor with a meter and replacing it if faulty. Can any one tell me if the fault will reset its self or do I need to go back to a indi dealer to have reset.

 

[mercedes13156]

If the fault is rectified, it should clear itself and your warning messages will disappear. The codes will more than likely be stored.