What is the FUSE for SAI Pump? 2.8L, A4 B5

[TheReflex79]

I attempted to search first, and came up striking out. I'm looking to find out what the fuse is for the SAI Pump in the fuse box located by the wiper cowl. I had the pump replaced this weekend when finishing up the timing belt. But come to find out the bad pump, blew the fuses. Any kind of help would be appreciated. Looking to finally clear my CEL!

The car is a 1998 Audi A4, 2.8l, 30v

[walky_talky20]

The fuse should be a large 50Amp fuse located in the 3 way relay carrier in the ECU plenum box, position number 7:



If it is the larger variety fuse, you might be able to test the system by borrowing the 40A cooling fan fuse from under the dash. Just an idea.

[TheReflex79]

Ok, last night I attempted to remove the ECU plenum box cover, I got the 4 screws that were visible out, about learn that there was one more in the box of the box. Is there any easy way to get to that screw and get the cover off? Or does the DS half of the wiper cowl have to be removed. Also will I have enough play in the box to get to that fuse?

[walky_talky20]

Yes, it is possible to get to the back bolt without removing the wiper cowl. You need a 1/4" drive ratchet and the perfect length of extension or deep well socket to reach the head of the bolt (screw, actually). You do have to take off the little metal clip on the far driver's side of wiper cowl to get enough "flex" to get your tool in there. Once you get the cover off, the fuses are pretty easy to get to. When removing the cover, do note that the relay for the SAI sticks up rather far, such that the cover will "catch" on it as you pull it out. To avoid damage to the relay or carrier, make sure the lift the cover as high as possible (flexing the wiper cowl a bit) as you pull it out. That way you can just clear the relay without any drama. Just a tip.

I elected not to put that rear most screw back in on my car, the other ones seem to seal it off just fine. Thiswas helpful as I've had to take the cover off 3 times total (chipped ecu, blown fuse, boost gauge install).

[TheReflex79]

I appreciate the help, I'll be attempting this as soon as I'm free from work. Good thing is that having a 2.8, I doubt I'll have to do this that much! At least I hope not.

[TheReflex79]

So as instructed I left the rear screw out, that was a pain to get out. Careful about taking off the cover, watching out for the relay, and there were no fuses in the box. I moved the ECU, and the only thing in the box was the was the relay, and 5 or 6 harnesses. Not sure if it's it's different between a 1.8, and a AHA 30v, but no luck finding the fuse. Any insight would be appreciated. And I searched 1st thing this morning as soon as I came into work. Thanks in advance!

[walky_talky20]

Hmm. Got the info from Bentley for a 98 30v. I hate that CD though, it is annoying to use. I'm sorry that info was wrong, that back screw is such a pain. Again, I do apologize. Just trying to help.

Mitchell lists the fuse as being a 50A under the driver's dash. I thought that was weird, as mine is definitely in the Ecu box. So I just went with Bentley on that one. Seeing as the relay is there, it would sort of make sense that the fuse would be there as well. Guess not. Dropping the kick panel isn't hard. Just a little screwdriver and 8mm socket and ratchet. In hindsight, perhaps I should have had you look there first, as it is much easier to get to.

[TheReflex79]

Yeah I peaked under the driver's dash, and was able to see a 50a maxi. So I'm guessin that must be the one. I'll pull it, and see if it's blown. Thank you for the help. I'll let you know how I make out.