GM TCCM Plugs & Wiring

Wiring diagrams and questions
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Tre-Cool
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GM TCCM Plugs & Wiring

Post by Tre-Cool »

Anyone have access to the GM TCCM plug/pin part numbers. Seems they used the same connector for the US & Aus vehicles.

Bonus if anyone can provide the 2016 onwards RG Colorado wiring schematics too, However i suspect anything from the US based vehicles will be very similar.

I am going to be doing an AWD project in 1 of my cars & the plan is to either use the MP3023 transfer case from a 2020 Silverado 1500 or the Colorado. I can buy a pre-made controller kit for the MP3023, but I have a couple colorado transfer cases at my disposal.

Here is what the Colorado TCCM looks like.
TCCM.jpg
Best i have found connector wise is JST J-2100 connectors, but they dont appear to come with any specific keyway. Looking at the above picture there is 2 different key ways on the 16 pin connectors, but none on the 4 pin.

16 Pin - https://au.rs-online.com/web/p/wire-hou ... gs/7122132
TCCM2-Plugs.png
4 Pin - https://au.rs-online.com/web/p/wire-hou ... gs/6028492

MP3023 Controller Kit - https://www.swaptimeusa.com/store/p25/M ... ystem.html
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radrace19
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Joined: Tue Apr 19, 2022 8:51 pm
cars: Pontiac G8 GXP

Re: GM TCCM Plugs & Wiring

Post by radrace19 »

J1 Connector
J2 Connector
J3 Connector

J1 and J2 are available. The problem is J3. It looks like Aptiv does not currently offer that connector. A pigtail is available from GM or ACDelco 19149301/PT2206 and can be found on Amazon.

Pinouts
J1
1 - Gear Position Sensor Low Reference
2 - Rotary Position Sensor Signal
3 - Incremental Encoder Direction Signal
4 - Front Axle Actuator Control
5 - Incremental Encoder Impulse Signal
6 - Four Wheel Drive Mode Switch 5V Reference
7 - Four Wheel Drive Switch Signal
8 - Not Occupied
9 - Gear Position Sensor 5V Reference
10 - Incremental Encoder Sensor 8V Reference
11 - Incremental Encoder Sensor Low Reference
12 - 4WD Locked Range Indicator Control
13 - Transfer Case Lock Solenoid Valve Control
14 - 16 - Not Occupied

J2
1 - 2 - Not Occupied
3 - 4WD LO Indicator Control
4 - Run/Crank Ignition 1 Voltage
5 - Not Occupied
6 - Accessory Wake-Up Serial Data
7 - High Speed GMLAN Serial Data [+]
8 - High Speed GMLAN Serial Data [-]
9 - 10 - Not Occupied
11 - AWD Indicator Control
12 - Neutral Indicator Control
13 - 2WD HI Indicator Control
14 - 4WD HI Indicator Control
15 - High Speed GMLAN Serial Data [+]
16 - High Speed GMLAN Serial Data [-]

J3
A - Transfer Case Motor Counter Clockwise Control
B - Transfer Case Motor Clockwise Control
C - Primary Fused Battery Positive Voltage
D - Ground
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Gatecrasher
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Re: GM TCCM Plugs & Wiring

Post by Gatecrasher »

I've had this happen a few times. Get the connector housing from a donor harness and then see if you can get the terminals by themselves.

Good luck finding crimp tools. I've got a few IWiss / iCrimp tools that get the job done, but they're not perfect.
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Tre-Cool
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Re: GM TCCM Plugs & Wiring

Post by Tre-Cool »

Thanks RadRace. that will help a lot. I do have a car i can grab the tccm & plugs from, but i wanted to be able to source just incase it's too hard of a job to get out of the car. I suspect it'll be spliced into the factory harness.

Do you know if the selector switch is using 33250071
TCCM-Switch.png
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radrace19
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Re: GM TCCM Plugs & Wiring

Post by radrace19 »

Tre-Cool wrote: Mon Jan 05, 2026 12:26 pm Thanks RadRace. that will help a lot. I do have a car i can grab the tccm & plugs from, but i wanted to be able to source just incase it's too hard of a job to get out of the car. I suspect it'll be spliced into the factory harness.

Do you know if the selector switch is using 33250071
TCCM-Switch.png
Uses GM part number 13525988

Here is the service manual info on that connector. I can't figure out the actual brand. It might be Molex or JST.
OEM Connector: 31410-0126
Service Connector: 13525988
Description: 12-Way F 0.64 Series, Sealed (GY)
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Tre-Cool
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Re: GM TCCM Plugs & Wiring

Post by Tre-Cool »

Nice, do u have the pinout for that 1 too?

While it has 12 pins coming out, i don't think they are all in use. I reckon based on the main TCCM, it's just a 5v ref, signal gnd, signal wire, Then prob the 4 indicator light controls along with either 12v,gnd or both.
radrace19
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Re: GM TCCM Plugs & Wiring

Post by radrace19 »

Sure do

1 - Sport Mode Switch Signal
2 - Run Ignition 3 Voltage
3 - Neutral Indicator Control
4 - Indicator Dimming Control
5 - LED Backlight Dimming Control
6 - Ground
7 - AWD Indicator Control
8 - 2WD HI Indicator Control
9 - 4WD HI Indicator Control
10 - 4WD LO Indicator Control
11 - Four Wheel Drive Mode Switch 5V Reference
12 - Four Wheel Drive Switch Signal
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Tre-Cool
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Re: GM TCCM Plugs & Wiring

Post by Tre-Cool »

Interesting they have Sport Mode Switch wired to that. Interesting...

Might need to pull the colorado apart to see if they run the tapshift/shifter to the 4wd switch.
radrace19
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Re: GM TCCM Plugs & Wiring

Post by radrace19 »

Tre-Cool wrote: Wed Jan 07, 2026 3:09 am Interesting they have Sport Mode Switch wired to that. Interesting...

Might need to pull the colorado apart to see if they run the tapshift/shifter to the 4wd switch.
Looks like the sport mode comes from the BCM
control switch schematic.jpg
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Sbornoe
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Re: GM TCCM Plugs & Wiring

Post by Sbornoe »

I am doing the same as you, only I have the MP1626XHD from 6.6 LML Duramax. Bought the harness from swaptimeusa 3 years ago, but still no luck getting it fired up as standalone. Because i am missing neutral signal and more from tcm, ecm and bcm, as these boxes needs handshake i guess. I am waiting for new Silverado 2016 LML tccm from US now, and will try some more. I am using a canbed Arduino/CANBed - Arduino CAN-BUS Development Kit (ATmega32U4 with MCP2515 and MCP2551) for trying to emulate can bus speed, neutral, prndl etc. but can’t find correct codes for it to read, also I had a tccm for the 3032 with Auto, and my MP1626 doesn’t have that. Hope my documents can help you, please share if you find a way to transmit data back and forth between tcm,ecm,bcm to tccm! Some pictures was to big, will try send again
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