Yamaha911

This is my first time owning an Audi S4 I was just wondering if it's a normal thing for the trans to shift almost like a muscle car would? It feels like it does some fairly hard shifts. It's a 2001 with 58K on it.

Kriation

Did the previous owner have it chipped?

If so, they may have neglected to remove the TCU before they sold it. It's a pain to get to, but the only way to find out [unless you can ask the previous owner] if the transmission computer is chipped is to remove the box, and look in it.

I had to remove mine a couple of months ago, and it wasn't easy, but eventually came out with a lot of elbow grease.

Yamaha911

I honestly have no clue. I'd have to call the owner up tomorrow. Where approximately is the TCU located? Like I said I'm very new to this type of car and I'm still trying to learn as much as possible. Thank you for your help.

Kriation

No worries.

The TCU container is underneath the front passenger side footwell, closer to the seat brackets than the firewall.

To get to it, you have to remove the door sill, holding the carpet against the floorpan. There are two/three screws in the plastic cover on the right of the footwell that have to be removed before the sill will come out. Once the screws are out, the sill is held in with clips; be careful when pulling the sill away from the floor plan. You'll hear each clip release; there's at least 4-5.

Once you have it away, you'll be able to reach your hand underneath the carpet, and start feeling around for a smooth plastic box.

The box isn't secured down, but it's in an indent, so you'll have to finagle it out. The first time I pulled it out, it took about an hour, but it was < 20 degrees out, so half the time, I was trying to keep my hands warm, plus, the carpet wasn't being very malleable.

Once you pull the box out [think of the mechanics of a baby being born naturally], there's one clip holding the harness into the box. Un-clip it, open the box, and you'll see the metal box that houses the actual TCU.

To open the metal box, you'll need a torx set. [I can't remember the size off hand, but a fairly complete set should have the size you'll need].

Once you take the screws out, there are four metal clips that need to be pried back, so that you can separate the top and bottom half apart.

When the halves are separated, and you're looking at circuit board, it'll be pretty clear [via stickers, or a DIP socket (depending on how the modification was done)] whether or not the chip is modified.

Good Luck!

complacentsee

The TCU doesn't use screws, the upper lid has fold-over tabs. That will probably break off after being used before.

You can run tip chips on any software. (well assuming they haven't modified the shift points. rev limit. ect) They need to match to insure you don't go into trans limp mode.

Kriation

Thanks for the fix.

I mixed up the torx requirement on the ECU box with the TCU box.