Looking for 2012 5.3 liter E38 Connector Pin Out

[Munchies]

I have learned there is a Brake Pedal Position Sensor.
X1 - 26 Brake Apply ~ Yellow wire Circuit 5361
X1 - 42 Brake Apply ~ Brown wire Circuit 5360
X1 - 54 Brake Apply ~ White wire Circuit 5359

I will need to disable the both P057C and P057D Brake Pedal Position Low / High.

I was not able to find a schematic for connector X1 - pin 09 brake switch.

dave w

Give me a year and model I will go for a quick dig.

[pmkls1]

Dave,

Glad you found what you needed for the diodes. As for your need for info on circuits I have a suggestion that may be of great assistance. You can actually buy a trial subscription to the GM Service Information database. It costs $20 for a 3 day subscription and given the nature of your project I feel that it is well worth it. If you were simply needing a couple wiring diagrams then $20 might be a little steep, but the intensity of your project warrants the cost IMHO. The amount of knowledge that you can obtain can prove quite invaluable because, aside from being able to view and print any and every diagram that you need, you can also view a detailed description and operation of any and all systems of the vehicle. The trial subscription gives you unrestricted access to all sections of SI so you can access any info that is available there. I have used the trial subscription once before when I needed some detailed repair info for a couple of my vehicles after my former employer had finally removed me from the GM system. I'll attach a link to the site where you can purchase the subscription and access everything. https://www.acdelcotds.com/acdelco/action/subscribehome

HTH,
Phil

[dave w]

Give me a year and model I will go for a quick dig.

2012 Silverado 4WD 5.3 Liter VIN 1GCRKSE77CZ259538

dave w

[dave w]

Dave,

Glad you found what you needed for the diodes. As for your need for info on circuits I have a suggestion that may be of great assistance. You can actually buy a trial subscription to the GM Service Information database. It costs $20 for a 3 day subscription and given the nature of your project I feel that it is well worth it. If you were simply needing a couple wiring diagrams then $20 might be a little steep, but the intensity of your project warrants the cost IMHO. The amount of knowledge that you can obtain can prove quite invaluable because, aside from being able to view and print any and every diagram that you need, you can also view a detailed description and operation of any and all systems of the vehicle. The trial subscription gives you unrestricted access to all sections of SI so you can access any info that is available there. I have used the trial subscription once before when I needed some detailed repair info for a couple of my vehicles after my former employer had finally removed me from the GM system. I'll attach a link to the site where you can purchase the subscription and access everything. https://www.acdelcotds.com/acdelco/action/subscribehome

HTH,
Phil

Hi Phil,
Thank you very much for the link!

dave w

[Munchies]

I am pulling a bunch of stuff, and saving it to a folder, but the ECM

[Munchies]

I am pulling up a bunch of stuff, but the ECM connector is labeled as X2 in all of my docs here.
I dont think I have had enough coffee.
Is this the donor?
http://www.salvage-cars-for-sale.inf...12-MTY4Mjk5ODM

Anything look right here?
https://drive.google.com/folderview?...mM&usp=sharing

foundx1 and added it. looking for the actual diagram now. Forgot how much alldata diagrams are a PITA. Downloading mitchell now lol

[dave w]

I am pulling up a bunch of stuff, but the ECM connector is labeled as X2 in all of my docs here.
I dont think I have had enough coffee.
Is this the donor?
http://www.salvage-cars-for-sale.inf...12-MTY4Mjk5ODM

I don't know if that was the donor vehicle. Could have been.

Anything look right here?
https://drive.google.com/folderview?...mM&usp=sharing

foundx1 and added it. looking for the actual diagram now

It all looks good. I found the same schematics also. I was not able to find a schematic showing where X1-09 (Circuit 6311) is connected to?

dave w

[Munchies]

It doesnt show up anywhere I can find except the x1 pinout. Downloading mitchell now

[Munchies]

Spoke too soon. I found it under cruise control finally.

See new file x1099 in link

[pmkls1]

Wiring diagrams are split up into their corresponding category so sometimes they can be difficult to locate. I.E. The wiring diagram for a brake switch input at the ECM from the ABS system may be found in the ABS category instead of the Powertrain Management category. Or, in this case, the brake input or output for the Cruise Control will be found under that category instead of Powertrain Management.

Also, to address a much earlier but critical question, the data communications in these late model systems uses a twisted pair wiring configuration that requires a 120 ohm terminating resistor at either end. As you can see in one of your diagrams posted earlier the ECM in this vehicle contains one of the terminating resistors, but in order to communicate with the modules the other end of the twisted pair must have a terminating resistor as well. I don't know about operating the ECM without a BCM, but I was under the impression that it was not possible because the BCM serves as a gateway module for all module communications and more importantly it is a power-moding module that manages the power mode for all modules on both the high-speed and low-speed LAN networks. This means that the ECM and TCM do not wake-up with a switched +12v power source, rather the BCM sends a wake-up command over the high-speed LAN network. I do not know how these modules behave without the BCM connected to the data lines. Yes you may be able to communicate with them, but will they wake-up and sleep properly ? If the modules don't switch to sleep mode, their rate of power consumption when awake would most likely drain a battery overnight.

[dave w]

Spoke too soon. I found it under cruise control finally.

See new file x1099 in link

Awesome find!

Thank you very much!

dave w

[dave w]

Wiring diagrams are split up into their corresponding category so sometimes they can be difficult to locate. I.E. The wiring diagram for a brake switch input at the ECM from the ABS system may be found in the ABS category instead of the Powertrain Management category. Or, in this case, the brake input or output for the Cruise Control will be found under that category instead of Powertrain Management.

Also, to address a much earlier but critical question, the data communications in these late model systems uses a twisted pair wiring configuration that requires a 120 ohm terminating resistor at either end. As you can see in one of your diagrams posted earlier the ECM in this vehicle contains one of the terminating resistors, but in order to communicate with the modules the other end of the twisted pair must have a terminating resistor as well. I don't know about operating the ECM without a BCM, but I was under the impression that it was not possible because the BCM serves as a gateway module for all module communications and more importantly it is a power-moding module that manages the power mode for all modules on both the high-speed and low-speed LAN networks. This means that the ECM and TCM do not wake-up with a switched +12v power source, rather the BCM sends a wake-up command over the high-speed LAN network. I do not know how these modules behave without the BCM connected to the data lines. Yes you may be able to communicate with them, but will they wake-up and sleep properly ? If the modules don't switch to sleep mode, their rate of power consumption when awake would most likely drain a battery overnight.

I don't have the schematic in front of me. I remember there is a pin labeled 12V IGN wake up signal from the ECM directly to the TCM. EFI Live allows the options to ignore (no error reporting) "Lost communications with BCM". I will learn very soon how this works / does not work.

dave w

[pmkls1]

After looking at the schematics you posted it appears that the BCM may simply provide a switched +12v signal to all modules on the network to power them on. If you notice in the schematics, the ECM actually provides the ground for the powertrain relay. Most of these ignition wake-up signals are simply discreet signals and do not carry a load, so that part at least isn't difficult to wire. All of the load-bearing circuits go directly from the fuse blocks and junction blocks to the individual modules with the ignition switch simply sending a +12v discreet signal to the BCM when switched on. So, it appears that the BCM is not necessary, but the second 120 ohm resistor definitely is. Where the resistors are located and their physical properties vary from vehicle to vehicle. Many vehicles have at least one of them built into one of the modules, but the second one is quite often located somewhere in the wiring or fuse block.

[Buzz]

... it appears that the BCM is not necessary ...

True.

... but the second 120 ohm resistor definitely is ...

False.

[pmkls1]

False.

That's not what I have found in my experience or what I was told by the GM engineers at the training facility.