rkreimer10

Hello all. I am active in the n54 community here. I am in this section as my friends 05 545i with an SMG trans and it is having issues. I hope my post is welcomed here!!!

I am getting a fault code: 4F75 GEARBOX, GEAR SELECTION NOT POSSIBLE

We cannot shift out of nuetreal but it sure is trying. When it would engage the Drive gear it would jump straight into second. Reverse is not possible.

What we tried:

Replaced the SMG Pump relay: # 1 in the picture. NOT WHERE MY FINGER IS POINTING



We replaced the MTF-LT2 trans fluid as it was low and black.

I had complete control of the trans with INPA and ISTA and could shift in and out of any gear I chose. But when trying to shift into gears with the gear selector switch the grinding and not engaging starts to happen. Hook the computer up and shift flawlessly with the keyboard.

I found a lose ground above the fill hole area, no change when tightened.

Other than 4f75 there are no faults or indications that anything else is causing the problem. Why can I control the trans with my computer but not the gear shifter?

Also what values should I be looking at? Any help is appreciated. Thank you in advance!!!!

domibln

Please, please, please tell me that you did not fill the MTF-LT2 to the reservoir of the SMG? This would damage your SMG system immediately. In this case you will soon have far more serious problems than the one described.

If not, here my advice regarding your problem: probably it's the clutch actuator (slave cylinder), which is leaking. The leak makes the SMG unable to engage the clutch which is necessary for gear changes in real situations (except the gear change via diagnosis, what you mentioned). We offer a rebuild with warranty for this part (on our website) because it's crazy expensive at BMW dealers. The faulty clutch actuator is a quite common failure of the Non-M SMGs.

rkreimer10

Haha....no I did not fill the smg reservoir with trans fluid.

it actually turned out to be a broken pivot ball.

how much is your rebuild service?