E40 ECM TO T43 PROGRAMMING SOLUTION NEEDED!

[Tre-Cool]

so verdict is the original ecu is pretty much rooted.

Luckily someone sent me a another e40 from a 2006 gto. so i've migrated what i had mapped out on the older os to the new one.

I'll see if i can break this one too, if i do this will get Tazzi to do the bdm coz my solder skills suck.

[Tre-Cool]

And i broke the new ecu now too..

This one still shows the ecu on the can bus at least, I can scan/log it in car, on bench. Just can't read or write to the ecu again.

I only did 4 CAN setting changes, so i doubt it's that. Suspect it's something to do with 1 of the other switches i changed which *should* be to do with PN safety switch and IMS.

My soldering skills are not good enough to get to the bdm pins, so I'm giving Tazzi that job. haha.

If there are motorola code experts i can send you some memory locations in a couple of Oses to look at in ghidra.

[roughneck427]

Good gracious you’re better off buying core ecms. Have you ever seen the inside of an OBDX pro? I

[Tre-Cool]

while its a PIA, im really only doing it out of self satisfaction to see if i can do it.

Ain't no body that would likely do the upgrade to a 6l80e in these particular cars unless they never plan on selling it.

Likely i'll end up repining the engine harness connectors to plug into an E38 & use the new RUSEFI unit as that will save having to change the crank/cam setup.

[Tre-Cool]

Spent some time at Tazzi's place today having a play with the BDM E40 & have found what broke the ecu's, no idea as to exactly why it breaks them, but it was related to me enabling some of the CAN RX id's the T43 controller transmits.

Isn't related to any specific ID, but rather the number order it's setup to listen in.

Could reproduce 2 states, No Connection, unable to detect with scan tool or flash & the same again but the scan tool knows the ecu is still there.

[Tre-Cool]

Got ecu back in this afternoon after working on another vz clubsport with a t400 conversion that someone did & just turned off all the error codes in the T42.

I went a little further and turned off the TX CAN id's, then changed the ABS & PIM modules to manual. That fixed up the dash & abs module errors.

As for the E40/T43 mule, it now wants to crank but the battery is stuffed. I'm pretty confident it will work, but since it's currently fitted with a 2011 TCM it's not able to broadcast ID's 150 & 151 which the T42's used in factory form. However I have no idea what exactly they are transmitting since non of the GM doc's have them defined.

[Tazzi]

Might be a matter of monitoring those ID's and see what they output over a period of time, or hook up some potentiometers over various sensors and see if they change when modifying.

Once figured out, it might be something that can be resolved with some basic hardware to simulate the output.

[Tre-Cool]

Might be a matter of monitoring those ID's and see what they output over a period of time, or hook up some potentiometers over various sensors and see if they change when modifying.

Once figured out, it might be something that can be resolved with some basic hardware to simulate the output.

The 150/151 Id's are transmitted from the TCM to the ECU, so it might be okay without them.

Heres a comparison of E40/T42 & couple of T43 cals. I have only highlighted the factory E40/T42 TX to RX setups. Red is ECU TX to TCM RX. Green is the opposite way.
Basically 4 ID's for the TCM TX Id's. 320 is mostly gear indication, sports/tapshift information to the PIM. 520 is Trans sensor data
TCM RX Id's are:
110 - Engine Speed and Pedal Position
120 - Engine Torque
124 - Unknown
128 - Brake info from PIM
131 - VIN Digits 10_17 HS from PIM
140 - ABS - Traction Control
280 - ABS - Wheelspeed
2C9 -
2F0 - ABS
300 - Engine General Status
380 - Platform General Status from PIM
510 - Engine Sensor Data

Screenshot 2025-10-27 202041.png

Well i feel slightly dumb. I do have the 150/151 CAN Id's, changing from dec to Hex they are x96/97.
PTEI_Trans_Clutch_Status_1 & 2.
Mostly has stuff related to clutch fill times & torque, not sure why the ecu would care though.. oddly this seems to be a holden calibration thing only. the US calibrations dont use these id's.

[Tre-Cool]

Success!

Sort of. Got the car running again, Initially i had no output shaft (wheel) movement despite the engine rpm & TIS reading when in reverse or forward gear. Now i have Reverse and gears 1-3.

It's a similar issue i found with testing the Link ecu out. So it's hopefully just a CAN ID bit length missing. Currently going through OS section byte length so i can do some comparison against some E38 code.

I'm still 90% certain im gonna need to put in an earlier T43 techm, but so far it's definitely looking possible for direct 6l80 support. Hell even traction control was kicking in and killing throttle until i turned TC off while on the hoist.

Also found that i had some existing can Id's wrong/missing as i wasn't getting ECT sent to the trans originally too. I check this by pulling ect, iat & other data from the TCM separately from the ecu.

Also have to check I got the TOS output from the TCM wired to the dash since i got that turned on too as the Dash speedo didn't work (checked tune file again, helps if i actually do have the TOS output on..) However ECM is getting speed from the box via CAN just fine.

E40-T43-Progress.png

[Tazzi]

Whoop whoop!! Great work!!!!

I hear the T87/T87A is a good candidate next