Hello,
Sorry for picking this up again. I want to share my story about the ATTESA Relay clicking issue. Maybe it helps someone.
Into:
My car was in the workshop for almost two years. Therefore, it was barely driven. Before that, I never noticed any attesa issues. After I got the car, back I noticed the clicking and after turning the ignition on that the pump running for several seconds.
Issues:
I never touched anything related to the attesa system since I got the car back. However, I noticed the clicking and by the time, it got worse. The AWD lamp was randomly on and AWD not working. When I started the car after it is warm AWD was working fine. Once I noticed oil underneath the back of the car on the attesa reservoir side. The attesa oil reservoir has the overflow valve in the cap which leaked the oil. I still not understand why I had an overflow there. After running the car for a few minutes the level in the reservoir got back to normal and I had to refill some oil.
Diagnosis:
After that, I had the car running and then touched all relays in the trunk area. The clicking one was obviously the attesa relays, which is located close to the trunk lid lock.
Therefore, I searched the web for a solution and found this thread plus several other ones that all say that the attesa pressure reservoir has a leak. Which does sound quite logical to me. I ordered a new reservoir.
Solution:
Due to some other issues while mapping (bad trigger signals) I decided to replace the engine harness. During the pull of the old harness, I noticed these plugs which sit in the fender area behind the headlight passenger side. The plugs connect to the engine bay harness that later connects to the main harness that powers the attesa system.
When I installed the new engine harness, I replaced these plugs against some nice sealed deutsch DTM plugs. Since otherwise the engine bay harness plug would have remained in that condition and I really don’t want to connect the fresh new engine harness to that filthy rubbish.
So new harness with new plus in and? No clicking and no pump running after ignition on anymore. New reservoir still sits in the shelf.
Conclusion:
MAYBE check and replace these plugs before doing any further action to solve this issue. Obviously I can’t tell if the engine harness itself or only the plugs where the issue. I think it's worth a try for everyone with the same issue.
