535i trans program error when started

[Eagle]

Hi

Ive recently done an engine swap and transmission swap from a '89 UK 535i to a NZ new '88 535i. Had no problems with trans on the other car
Everything is fine apart from when i start the car i get the trans program error as soon as the car is running.

Cleaned contacts and swaped the relays but im guessing must be something more major if it comes up right away.

I was thinking of swapping the transmission computers?, any other thoughts or idea would be appreciated

Cheers
Jared

[Kalevera]

The '88 most likely has the late E7 version of the AEGS software, while the '89 almost certainly has E9. Swap the valve bodies between the transmissions and see if that works. There are physical differences in the wiring, which is intertwined with the body harness.

best, whit

[Eagle]

Thanks for the advice, i replaced the older tranny computer with the newer one from the other car and the error disappeared