my ecu/tcm's arrived while i've been away for work, along with the can interface module to do them. I might have a play while im home. Also found a place that sells a 10l80/90 to tcm harness for $110usd. gonna have to send them an email as they don't list international shipping. https://topstreetper...

so small update. new harness is on. modified trans tune to show up gear shift positions correctly. flashed update to ecu with new cal settings. ecu no longer responds to programming or scanning, but it still transmits on the can. no idea wtf has gone wrong there. so have cracked the case open to bdm...

I've got the global-a can dbc. the log files will have the tx & rx comms between tcm-2650 & the TCM itself.

I'm going through the data from the link-tcm log now to see what could be wrong.

new harness is 80% in.

just need to run it into cab and connect to ecu. then flash tune in and see if it at least starts.

Heres some can data logged from a car with a tcm2650 standalone controller & 6l80e. Theres quite a few can id's with fixed data that never changes, these are likely to keep error codes from being flagged by the trans for various os/calibrations for missing modules like EBCM,BCM etc. it can emula...

well I spent $640 on ebay by ordering an e90,t93 & t87a. for when i get around to doing something with a 10 speed & L87 engine in the next few years...

if you could reprogram it, I'm sure it would be possible as it does have inputs. Pin Wire Colour Circuit No Function 1 Light Blue Power/Economy 2 3 Red/White Traction Control 4 Grey/Green Cruise Control On/Off 5 Green Tran Control 6 7 8 White/Black Cruise Control Resume\Accel Switch Signal 9 Blue Cr...

yeah. our early pre 2006 cars used single wire uart comms between abs,bcm,dash cluster so there was a pim module to translate between vpw and uart comms. in 2006 a new pim was introduced to do CAN 2 uart comms, but the early can used different can id's to what the later ecu/tcm os calibrations used ...

i had entirely forgot that i had purchased 2 of the u-links since i had never got around to opening up an e38, so they've been sitting in my desk drawer at the workshop. As i have an E38 that would get hot and do wierd stuff in a car & was fixed by replacing it, I have a good candidate test open...

just did write up here.
https://www.torqueup.net/2025/04/25/gm- ... bus-comms/