amiram

I would start fault code P1602, Terminal 30 is connected directly to the battery, check the battery connections and the Charg level. Check out the negative battery connection to the vehicle body. " P1626 - 35-00 - Missing Message from TCU" There is a possibility of a bad electrical contact in the socket and plug on the gear box

glennlindh

Well, the battery connections are "as new", perfect shape, I disconnected them and make it sure that they were clean and sprayed and greased(electric grease) them so they are good..
Both sides, and body mount..
I have not checked the gearbox connector yet, did not think of that one..
I just need to find where it is connected

5v/cyl

The connector is on a bracket next to the tranny pan, but that won't cause this problem. The TCM would list a fault code. You can't even communicate with the TCM. Sounds like a power short, lack of power, or just bad TCM. Check out this thread to see if it helps at all: https://www.audiworld.com/forums/s4-...cause-1621319/

glennlindh

Yeah, I read this guys solution/problem, but mine was totally as new, tabs locked down nicely etc.. But now they are broken, after my checkup, so I better tape them down good!

I have something different, but what.. hmm..

glennlindh

Ok, long time since last..
I got a new TCU harness, or ; WIRING HARNESS FOR 5-SPEED; AUTOMATIC GEARBOX
Now I pulled all the harness from the TCU down to the firewall, but I can't find the cable on the other side! Anyone that knows how it is routed??
It is the round connectors that what I guessing is the gear box connector etc..
I would like to see some pics or so..

Happiegolucky

I have the same exact problem, No first gear, and the under the passenger side carpet is wet any time it rains! Has anyone figured out how to fix this?

Happiegolucky

I also feel a thud when putting the Allroad in gear

glennlindh

Update, sorry it took so long time..
But here it is:
I took out that harness (took apart the whole car pretty much! ) and finally got the new harness in..
Do You know that the Audi have "2 firewalls"? well.. once you got the grommet out, slid away, the harness goes thru the steering ram tunnel, and under two (2) again walls/innerfenders, like thru a tunnel up front..
To take the old harness out was kinda simple, I wasn't so careful then.. just pull and twist and pull etc..
BUT!? when trying to feed the harness/connectors back!... ha, thats a pain in..
well, after work and dark thoughts, it is in there..
Connected all together, ok no seats or airbags, carpet, etc..
Do You think it worked??
Same stupid story!!!
3 Faults Found:
18034 - Powertrain Data Bus
P1626 - 35-00 - Missing Message from TCU

18010 - Power Supply Terminal 30
P1602 - 35-00 - Voltage too Low

18058 - Powertrain Data Bus
P1650 - 35-10 - Missing Message from Instrument Cluster - Intermittent

Ahhh poop!!

The instrument cluster is still just unconnected, but even then I do, this two (2) continues:
18034 - Powertrain Data Bus
P1626 - 35-00 - Missing Message from TCU

18010 - Power Supply Terminal 30
P1602 - 35-00 - Voltage too Low

ANYONE HAD THE SAME SCENARIO??

I'm out at Oregon coast and I don't think it is any shop that have experience enough here for this fixing, You have any connections or thoughts, I starting to give up...

glennlindh

The plug on the tranny is "new", I took the best one I had and connected it to the harness, I checked and double checked the harness, BEFORE I put it in..
The connectors to the battery and the ground on the tray is as new..
So I don't have more ideas...

glennlindh

Do You know there exactly this red Terminal 30 cable is routed? I just found the red one at the harness for the TCU, and mine just gives 7.8-8volt..