Looking for 2012 5.3 liter E38 Connector Pin Out

[pmkls1]

Dave, after looking at that schematic I can tell you that the diodes are either integral to the fuse block OR the more likely possibility is that they plug into the fuse block like standard blade fuses. I have seen many later model fuse blocks that have diodes in them. I don't have a part # for you, but you can salvage lots of them from various later model GM fuse blocks. I more than likely have a few of them in my toolbox that I'll take a pic of later when I head down to the basement. The purpose of the diodes is to isolate the two fan circuits from each other so that the ecm can turn on fan1 on a low speed with one output and turn on both fans on at full speed with a second. Without getting all crazy with a drawn-out explanation, the diodes are crucial to proper operation with that particular wiring and solenoid configuration.

On a related note, I do have a little bit to add on your other threads pertaining to this same project that you're working on. It will take me a while to type up those posts though, so it will be later in the day before I can reply to those topics.

Hope I was helpful,
Phil

[dave w]

I was looking through the harness for the Transmission Control Module (TCM) plug, then I learned that the TCM for the 6L80E is inside the transmission ... the internet is usually a good source for information? It might seem odd to some members that I did not know where the 6L80E TCM was. My main role in this conversion is wiring and the computer flash (the fun stuff).

dave w

[Buzz]

... the TCM for the 6L80E is inside the transmission ...

Yes sir ... 6L80/90 TCM connector looks like this ...


Attachment 7012Attachment 7013

[brian617]

I was looking through the harness for the Transmission Control Module (TCM) plug, then I learned that the TCM for the 6L80E is inside the transmission ... the internet is usually a good source for information?

dave w

Makes it a pain in the ass when replacing a bad transmission. Have to haul truck to dealer to get replacement trans/TCM flashed so it will communicate with ECM.

[Buzz]

The T43 actually isn't too oppressive to work with. The newer ECMs (E38 / E67 / E78 / E83 / E92) need a GM dealer / TIS flash if replaced - as tuning software cannot read / write the throttle control portion (second core) of the ECM.

The T42 / T43 / T76 TCMs can be completely reflashed using tuning software - making them a little more user friendly.

[dave w]

I've noticed some "brake" related pins in the E38 computer.

The pins I have questions about are on the X1 connector (Black 73 pin connector):
X1 - 26 Brake Apply
X1 - 42 Brake Apply
X1 - 54 Brake Apply

Are the above pins inputs / outputs from ABS? Are the above pins inputs / outputs from somewhere other than the ABS?

The other pin I have a question is:
X1 - 09
I'm thinking this is from the brake switch and in a Normally Closed input to the E38 computer?

Thanks,
dave w

[Buzz]

I've noticed some "brake" related pins in the E38 computer.

The pins I have questions about are on the X1 connector (Black 73 pin connector):
X1 - 26 Brake Apply
X1 - 42 Brake Apply
X1 - 54 Brake Apply

Are the above pins inputs / outputs from ABS? Are the above pins inputs / outputs from somewhere other than the ABS?

I believe that these are generally not used with E38 non-Hybrid trucks. Hybrid uses pin 54 for fan control. V6 trucks (E37 ECM) does use these pinouts.

Can you post the schematics your question is based on ?

The other pin I have a question is:
X1 - 09
I'm thinking this is from the brake switch and in a Normally Closed input to the E38 computer?

Thanks,
dave w

Gen IV brake input logic is the opposite of Gen III.

Gen III PCM receives 12 volts when the brakes are NOT applied - and this circuit is interrupted when the brakes are applied - a Normally Closed circuit.

Gen IV ECM / TCM receive 12 volts when the brakes ARE applied - and this circuit is interrupted when the brakes are released - a Normally Open circuit.

[dave w]

I believe that these are generally not used with E38 non-Hybrid trucks. Hybrid uses pin 54 for fan control. V6 trucks (E37 ECM) does use these pinouts.

Can you post the schematics your question is based on ?

I do not have schematics, I'll need to research (visit my local public library) for the schematics.

dave w

[dave w]

The pins I have questions about are on the X1 connector (Black 73 pin connector):
X1 - 26 Brake Apply
X1 - 42 Brake Apply
X1 - 54 Brake Apply

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

[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.