Electromechanical steering rack problem and getting it fixed.

[LarsE]

Hi,

I am experiencing problems with my B8.5 steering rack, it's making noises at standstill and low speeds and it's binding when driving straight roads so it's annoying just keeping a straight line. It also throws a fault code telling it's a mechanical fault.
Now I need to replace it, a new one here in Finland is 3500 € from the dealer. From Germany I can get it a fair bit cheaper but still an original part.
But the main question is, has anyone here swapped it by them selves and what about coding the J500 control unit? Service manual tells to run the "J500 Replace control unit" program using the "Guided fault finding" function. I can't find this program in VCDS so is this job a dealer only thing?

 

[spartacus 68]

I hope I never have to do this job. If I did - I would only do it with 2-post lift. Apparently electric pump suffers from water damage. One option may be to go for a refurbished unit, at least that way you're dealing with rebuilt Audi unit, rather than going down aftermarket route. I don't know this company - just giving an example.

Audi A4 B8 Electric Steering Rack Reconditioning Service | Western Power Steering

Audi A4 B8 electric steering rack reconditioning service of your own part, complete electric and mechainical rebuild to OEM standard

shop.westernpowersteering.co.uk

Pretty informative video here on dismantle and refit:


Interestingly, ensure steering wheel is centred - and don't adjust with the rack off or it will throw the clock-spring.

Can't answer your query regards J500 control unit (my understanding is it's part of the pump). Pretty sure you should be able to use VCDS. Hopefully someone can answer for you.

 

[LarsE]

I'd say the job is very doable on jackstands aswell as the unit weighs somewhere between 10-15 kg. Main problem is the coding part, I have VCDS but didn't find anything refering to "J500 replace control unit" when checking.

 

[spartacus 68]

More details here on Rosstech. Retrofitter NHN on here may be able to add details.

My understanding is the J500 unit is part and parcel of the steering rack. Importantly - a healthy battery is essential, so potentially put the battery on trickle charge. The car tracking should be done on completion and all previously stored DTCs cleared that might have been linked to the old pump.-

Also important - is the correct pump for the car. Getting access to the part code on the existing pump will be critical. Main dealer should be able to confirm.

Audi RCEPS Steering Assist - Ross-Tech Wiki

 

[LarsE]

Yes the J500 is integrated in the steering rack. I have a week old battery, the old one was the original I guess and during wintertime cold starts it was noticably weaker. Also threw a code back in january. I guess it might have something to do with the steering rack breaking down.