Turning on E67 Discrete inputs

[GSRegal99]

Here's some information on turning on the discrete input on an E67 for cruise. It is possible to turn on the discrete start request input as well, but I do not know the exact location at this time. I'll update this post once it's found.

GM used 3 different ways to trigger cruise on the E67 (that I know of).
CAN = 2
Single wire discrete = 1, Connector X1 Pin 29 (with a resistor ladder)
Three wire discrete = 0, Connector X1 Pins 21 (Resume/Accel), 22 (Set/Coast), 30 (On)

On OS 12630367 - 2009 Pontiac G6 the cruise bit is at 1D108B. (For my swap changed it from a 2 to a 0 for a 3 wire cruise switch).
On a 2009 CTS V and 2010 Colorado it's located here: 1D0A7B.

I pulled up those bin files and the string right before the cruise bit was the same (red is the cruise bit). 00 00 00 FF 00 02 (2 is the cruise type in this example). Hopefully that'll help you find it if your offset is different.

[Knackersjewels]

Any idea of other inputs that can be changed/added? like say, engine oil temperature, and discrete flex fuel signal?

[Knackersjewels]

And just adding, on the 2008 Acadia OS 12626281, that cruise byte is at 1D13F5

[zack4200]

Any idea of other inputs that can be changed/added? like say, engine oil temperature, and discrete flex fuel signal?

I don't know about enabling/disabling them, but I recently went through a bunch of E67 pinouts and made a spreadsheet on Google Sheets comparing the differences... Should give you a pretty good idea of the different inputs/outputs available. There might still be some more that are still missing, I haven't gone through every vehicle/platform that uses the e67. If anyone wants to add to it, feel free to request editing permission.

There are also few other tabs with similar comparisons for other PCMs, most of it was inspired by ejs262's post with p04 pinouts either here or at gearhead-efi (or both? lol).

[Knackersjewels]

Thanks, I'll have to do some diving. I know there is a flex fuel discrete pin on x1-5, and in your 09 CTSv LSA, it's got engine oil temp, so I may have to get some more hpt credits, and have a play around. Would be very nice to add boost control options to factory NA setups

[koolky]

I have been working with OS 12618164 which covers the LS4 Impala and GMT360 platform (Trailblazer 4.2L, 5.3L and 6.0L).

The 4.2L LL8 come factory with an oil pressure switch vs a sensor like the V8. I found and tested the switch at address 1D2DF4, 16 bit, 255=Switch X3 Pin 65 / 511=Sensor X2 Pin 60.

I also found and tested Oil Temperature Type switch - Defines ECM Connector X2 Pin-65 Assignment, address 1FE062, 16 bit, 0=Engine,1=Transmission, Engine Oil Temp CAN ID = 22153E. I used this on my 4.2L LL8 swapped car to data log EOT and display it with the TorquePro app.

With the help of this thread, I think I found the cruise control type switch at 1D0E0D, 8 bit (wondering if it is one address ahead and should be decoded 16 bit?) GMT360 value = 0, Impala value = 2.

I haven't used Ghidra yet, but are you guys using it to find these parameters? I would really like to find a way to convert to discrete AC request but I don't see any E67 platforms using it.

[MPC001]

Any idea of other inputs that can be changed/added? like say, engine oil temperature, and discrete flex fuel signal?

FYI don't know if this is what you are after, but anyway:

12618164 08 TBSS Flex Fuel on=1/off=0 is 1D1222, sensor type hard=1, virtual=0 is 1D1223
12632176 09 CTSV Flex Fuel on=1/off=0 is 1D0E92, sensor type hard=1, virtual=0 is 1D0E93

If it is what you are after, which OS?

On oil temp, you after the switch that defines ENG OIL TEMP Vs TRANS OIL TEMP?

[AngelMarc]

I would really like to find a way to convert to discrete AC request but I don't see any E67 platforms using it.

2014 Express Vans use an E38, but use old school vacuum flaps. Don't know if that could be used to find clues.
Enough work with ghidra and you should be able to swap a CAN bus message for a toggling of an unused pin to make it work. Same with inputs.
EDIT: It's just the input (ac request) isn't it? Not sure how hard it is for a skilled Ghidra user to track that don't and bridge the gap.

[koolky]

The 2008+ Express vans (possibly through current models) use the same BCM as GMT900 vehicles and do support a discrete AC request input. I’ve confirmed that a 2008 GMT900 E38 can receive the AC ON request data from a 2008 Express BCM. The problem that I have is that the reverse light request from the ECM or TCM (not sure where the message broadcasts from) will not trigger the van BCM. Keep in mind that the 2008 van BCM would have come from a van with a T42 since the T43 didn't end up in the vans until 2010. I am going to look for a BCM from a 2010 gas Express van and see if I can get AC request, TUTD, reverse lights and cruise to work with my 2008 E38+T43.

I just started using Ghidra to reverse-engineer the E67. I received an address for the AC-request switch (CAN vs discrete), wrote a CAX, and programmed the E67. After flashing, I probed power and ground and watched the scan tool for the AC-request signal, but didn’t see the discrete input become active. I’ve decompiled and inspected the code that references the switch address in Ghidra but can’t determine which input pin corresponds to the AC type switch. Any pointers on how to trace the code back to the physical pin would be appreciated.

[Tre-Cool]

I can tell you that it's the transmission that sends the gear over can, not the ecu with an auto.

The early T42 had the reverse lights wired through the NSBU switch on the side of the box, T43 controllers broadcasted the gear info out on a different CAN ID vs the later OS code too.

Luckily you can turn the old CAN ID broadcasts back on, but i dont think this will work with your BCM unless it's wired into the CAN?.

It's the same thing i went through to get the VZ PIM (CAN/ALDL Gateway) to work with later ECU/TCM code.

https://www.torqueup.net/category/tuning/