LS2/4L65E Swap c3 vette
Thread Starter
12 Second Club
Joined: Sep 2008
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From: Denmark
LS2/4L65E Swap c3 vette I have a bit of a problem. Im in the wiring process of my LS2/4L65E swap.
My problem is the TCU(trans control unit) needs TPS(throttle position sensor) input to determine shift firmness and shift points. As the installation sheet expains i have to splice the wires from the TPS connector from the tranny with my factory TPS wires.
I can't seem to find those factory wires.. However, there is a bulkhead connector from the ECM that has a purple wire for throttle position output. So im guessing i have to splice the wires from the TCU's TPS connector into the ECM's TPS output wires in the bulkhead connector.. Does it make any sense so far!
My concern lies in the fact that the TCU has 3wires. Red,White,Black.
The bulkhead has only one output wire.. Purple.
I know the Black is ground and is of no concern. But which of the redor white wire will go to the purple?
My own solution is in splicing the TCU's white TPS wires with the white wire on the bulkhead that is rpm output from the ECM?
Please give me some pointer of some sort so i can go to sleep tonight as a happy man
My problem is the TCU(trans control unit) needs TPS(throttle position sensor) input to determine shift firmness and shift points. As the installation sheet expains i have to splice the wires from the TPS connector from the tranny with my factory TPS wires.
I can't seem to find those factory wires.. However, there is a bulkhead connector from the ECM that has a purple wire for throttle position output. So im guessing i have to splice the wires from the TCU's TPS connector into the ECM's TPS output wires in the bulkhead connector.. Does it make any sense so far!
My concern lies in the fact that the TCU has 3wires. Red,White,Black.
The bulkhead has only one output wire.. Purple.
I know the Black is ground and is of no concern. But which of the redor white wire will go to the purple?
My own solution is in splicing the TCU's white TPS wires with the white wire on the bulkhead that is rpm output from the ECM?
Please give me some pointer of some sort so i can go to sleep tonight as a happy man
TECH Resident
Joined: Jun 2004
Posts: 841
Likes: 2
From: Tampa, FL
What in the world are you using for an engine computer and transmission computer?
What harness are you using?
Did you switch to a cable throttle body? If not, what are you using to try and run all this stuff?
What harness are you using?
Did you switch to a cable throttle body? If not, what are you using to try and run all this stuff?
TECH Resident
Joined: Jun 2004
Posts: 841
Likes: 2
From: Tampa, FL
Wow.... I guess you had a bunch of money to burn.
The instructions don't say?
From the sounds of what you described, after reading back through it, The red wire from the TCM is probably ignition or battery power. The white wire I would think is for engine RPM, but if not, then I guess it is the TPS input.
The TCM kit doesn't have any instructions explaining the wires?
The instructions don't say?
From the sounds of what you described, after reading back through it, The red wire from the TCM is probably ignition or battery power. The white wire I would think is for engine RPM, but if not, then I guess it is the TPS input.
The TCM kit doesn't have any instructions explaining the wires?
Thread Starter
12 Second Club
Joined: Sep 2008
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From: Denmark
I like to buy new GMPP parts because it will hold up to its promises. Unlike some aftermarket companys.
The instructions that comes with the engine and tranny are however not top notch. At least not for me and my knowledge. It says the basics but you have to think a little beyond that sometimes. The parts (engine and tranny plus computers and wires a top of the line premium quality.
I have already tried and do it as you described Jones,n. Figured it wouldnt kill me and try and ask in here. If the start up shows any problem i will know where top look though.
thanks.
The instructions that comes with the engine and tranny are however not top notch. At least not for me and my knowledge. It says the basics but you have to think a little beyond that sometimes. The parts (engine and tranny plus computers and wires a top of the line premium quality.
I have already tried and do it as you described Jones,n. Figured it wouldnt kill me and try and ask in here. If the start up shows any problem i will know where top look though.
thanks.
TECH Resident
Joined: Jun 2004
Posts: 841
Likes: 2
From: Tampa, FL
Top of the line quality because it is made in mexico? Or top of the line quality because it is the exact same materials (wire, connectors, terminals, etc) that are used by the aftermarket companies like Speartech? Or did you mean top of line quality because of it's customer support? Is there a number in the instruction sheet to call and talk to the person that built the wiring or programmed the computer to answer your questions?
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Verdad Gallardo TECH Resident
Joined: Jun 2004
Posts: 841
Likes: 2
From: Tampa, FL
aaahhhh... gotcha..
Well, let us know what you find by trying it as mentioned.
Maybe if you can post up a copy of the instructions for the TCM where it says what the wires do, that might be of some assistance.
Part of the reason I am assuming the purple and white wires are the connecting point, is that I am thinking when GM designed the harness, and put those wires in there, it was so they could be used together. One would think though, that they would have made them the same color to lessen some confusion.
Well, let us know what you find by trying it as mentioned.
Maybe if you can post up a copy of the instructions for the TCM where it says what the wires do, that might be of some assistance.
Part of the reason I am assuming the purple and white wires are the connecting point, is that I am thinking when GM designed the harness, and put those wires in there, it was so they could be used together. One would think though, that they would have made them the same color to lessen some confusion.
On The Tree
Joined: Jan 2007
Posts: 116
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From: Florida
What GM part numbers do you have. I thought the plug and play would control both eng and trans depending on what you ordered. My 5.3 has one PCM and no TCM and I love it. HP tuners is my best friend for tuning both eng and trans.
TECH Resident
Joined: Jun 2004
Posts: 841
Likes: 2
From: Tampa, FL
The GM Engine controller kit for the LS2/3/7's only runs the engine, and can't be tuned by HP Tuners unless you have someone reflash the computer with a VIN from a car and then start over.
In order to run a transmission, you have to get their separate trans controller system.
This is what he is trying to get to work together.
It's not like the older LS1's and such where 1 computer ran both.
In order to run a transmission, you have to get their separate trans controller system.
This is what he is trying to get to work together.
It's not like the older LS1's and such where 1 computer ran both.
On The Tree
Joined: Jan 2007
Posts: 116
Likes: 0
From: Florida
The GM Engine controller kit for the LS2/3/7's only runs the engine, and can't be tuned by HP Tuners unless you have someone reflash the computer with a VIN from a car and then start over.
In order to run a transmission, you have to get their separate trans controller system.
This is what he is trying to get to work together.
It's not like the older LS1's and such where 1 computer ran both.
In order to run a transmission, you have to get their separate trans controller system.
This is what he is trying to get to work together.
It's not like the older LS1's and such where 1 computer ran both.
