Probs after engine replacement

[selkent1]

Hi all

Just recently replaced the engine in my 2003 3.0i following a long saga of trying to diagnose a missfire and the result turned out to be anything but. I have anther thread on here detailing this. However, the engine was refitted and running just as it should but immediately i got the dreaded "Trans Failsafe Mode" message upon the dash when i started. Also the gear selector lights on the dash dont light up and tell you what gear your in. A couple of times it has lit up for a second or so but thats it. The car is drivable but it feels like its only using one gear but goes into reverse without any probs.
I knwo that theres a lot that reports to the gearbox ECU and can cause this, like the MAF or the throttle body. But if it was those things i would get codes for them and im not. I only have a generic reader and no codes are showing, with no warning lights on the dash.

I know people are going to say to put a reader on it or get it to a dealer but im unable to at the moment. So, anyone got any ideas????

Cheers peeps!

[selkent1]

Hi all (again)

OK, so i just put ISTA on the car and i initially started off with 70 plus errors, which after a few wipes ended up with about 10. Most of those were issues relating to the factory audio, which is no longer there and some errors relating to the instrument binnacle. However, i got no engine errors but i did get one for the TCM. It kept saying that it was unable to communicate with it. I erased codes and re read again and again and the result was still the same. Im no expert with ISTA, but would that indictate that my gearbox ECU is knackered?

And could it be as simple as getting a used replacement, from the same car and popping it in? I know that BMWs are never that simpple but givent he journey ive had with this car, it would be nice!!!!!

[andrewwynn]

The usual cause of that error is a dirty connection to the transmission. The clue is the prnd display on the dash.

With code reader that shows the real-time values of the gear selector it will seem scrambled. Mine was full of rusty water. It happened twice after a big splash of water from passing car obviously the freeway and once when car sat a long time wearing for a repair.

The connector can be reached from under the right front door if you drive into a curb at a driveway how I fixed while on a drive.

[selkent1]

Thanks for the reply

However, i went looking for said dirty connectors and came accross another post elsewere regarding fuses. I had a look and there is a group of fuses located inside the box containing the TCM. These consist of 4 30amp fuses and one 20 amp. I noticed one of the 30amp had gone. I replaced it and the selector light on the dash came on and went out again after a few seconds. I checked the fuse and it had gone again. Going by something i had seen elsewere, i unplugged the two oxygen sensor connectors that live in the top of the engine and low and behold, the fuse didnt blow and the car was fine. I gather there is a short in one of the two wires.