Resetting TCU

Does anyone know how I can reset the transmission control unit (TCU)? Does pulling out the fuse work? Where can I locate the right fuse?

What are you trying to achieve?

I susupect my TCU has gone beserk. I want to try resetting it to see if it works, like rebooting a computer.

There should be a fuse diagram in your fuse box. If not you can download one from the files section here. Disconnecting the battery will also reset everything. But why do you suspect your TCU has "gone berserk"? If you describe the problem maybe someone else has had similar issues and can help before you experiment.

The Tiptronic Control Unit has a couple of fuse assignments: Row B8 and Row C5, however, I would also just disconnect the negative lead on the battery for a couple of minutes, to see if that accomplishes anything.

PSM, ABS, PASM all failing, gearbox in limp mode. Everything fine until I left the car idle for more than 3 months, battery completely drained. After putting in a new battery , this thing happened.

Did you replace the battery with an OEM? Is it fully charged? How far have you driven since battery replacement? It takes a few blocks to get reset.

I am not sure if battery is OEM or not. My workshop did it for me. I have driven tens of kilometers. I pulled out all the related fuses for a day. The problems still there. The error codes I am getting are: PSM: 4211 speed sensor rear right, C1 control module faulty PAS: 8004 SC+, C1 control module faulty PASM : C203 fault steering wheel, C1 control module faulty Really scratching my head.

I'm sure u considered this, but why dont you just go to your dealer and have them worry about it?!

Also noticed from another post that you have had a new steering wheel installed. Did this start right after that by any chance? Perhaps the steering wheel sensor was damaged? That could cause those problems. As nitro said above the dealer is an obvious choice at this point. For DIY try disconnecting the battery , waiting and reconnecting and go drive. While you are doing that find out if you have a correct replacement battery in the car. It may be the wrong replacement or defective so who ever installed it should check it or replace it. However, your "workshop" should not have sent you out if the car was not working correctly so I'd be concerned about them. They may have also messed up a critical module of some sort. Sounds like there may be more to this story than we know.

Car gone to dealer today. Immediately they called back to tell me they can't access the ECU , with their equipment? What the heck? It has nothing to do with swapping steering wheel. The problem was there all along.

Titanic, Sometimes when the battery has been dead or disconnected for a long period of time the gateway can loose it's coding and will need to be reprogrammed with PIWIS . From the fault codes and now the dealer saying they can't access the tip ecu , this may be your problem. Once the gateway ecu is reprogrammed, all the installed ecu 's should be accessible again and be able to clear the faults stored. Good luck.

Spoke to dealer about your suggestion. They told me it was impossible. Even for cars left alone for six months. They need to run more checks and possible swap some of the DMEs. My car is a unique case according to them.

Latest update: my car is back after three weeks. Dealer went down wrong track of assuming faulty TCU. The hassle of sourcing a replacement TCU from head office is an absolute nightmare. In the end, it wasn't the TCU, and it wasn't any other control module, it was the wheel hub bearing at the rear sending wrong electromagnetic signals to the PSM. Heads up for any of you getting PSM/ABS CEL and transmission limp, check the wheel hub bearing. I still don't know how the bearing got damaged.

Bearing may not be damaged just pickup weak.... and not getting strong reliable signal for wheel revolutions. Sincerely, Rockster.