Do you know what Rheingold is, before you declare that 'you don't have access to it"?

Did you replace the 10A fuse? You open the fuse block, FIND THE BLOWN FUSE, replace it.

There is an online manual, star here: https://www.newtis.info/tisv2/a/en/e70-x5-3.0d-sav/

Again, did you replace the fuse or not? What happened when you replaced it?

F04 is the 10A fuse

That's perfect Ingenieur, thanks! I'm working on getting Carly or Rhienhgold, but in the interim I'd like to keep going if possible with some diagnostics.
If I go through through the items on that circuit, replace the fuse and start unplugging the items one by one to see if the fuse doesn't blow, am I going to get myself in trouble? I don't believe it's the scr that's the running issue. I know the person I bought it from told me the scr want working properly. It drove great when I bought it, now it has a really rough idle and went into limp mode once.
I think the transfer pump might be the culprit? I checked the service history on the vehicle and the active tank was replaced in December of 2015. It shouldn't be an issue after just a year and a half? At least, I hope not!
Is the transfer pump from the passive tank to the active tank under the passengers side floor in front of the air suspension compressor?

See if it holds, and I think you need to reset the codes with rheingold/ista or carly. A generic obd scanner can't always clear the codes.

Then you can see what codes come back. Idle issues and limp mode are hard to know without seeing the codes.

Sorry, haven't had my usual amount of coffee yet, so I might not be following. I feel like you're jumping to the conclusion that if the fuse blew, it's going to blow again and you're inspecting items down the line. Start with just replacing the fuse. I haven't seen if you've done that yet or not.

Lol

I've been saying/asking that for two days in two forums.....

has anybody said to replace the 10 amp fuse yet?:D

btw without Rheingold you are just like mice looking for cheese without a nose.

I think he should start by replacing the 10 amp fuse if he hasn't done so yet :eeps:

How many miles do you have? If its under 120k miles take it to dealer and have them fix the SRC active tank. That will take a bit so they will give you a rental, go to your trip with the rental if possible. Time it out that way if you are covered for the active tank repair.

Not so simple....