4L60E Torque Converter
 

Are the internal wire harness the same for a 2003 and 2008?
I am having trouble with a 741 code TC stuck off

The trans computer is a T42 and is for a 08 and my trans is 2003 is there any wiring/harness difference
that would cause a 741 code?

The trans is an upgraded/rebuilt from a local builder that has built trans for me for many years, before I go to him I am trying to dot all the "I" and cross all the "T's"

The trans does go into lock up at 55mph for a short time 20 to 30 min of driving, but if I go to WOT "I think"
this is where things happen!
3rd and 4th seem "confused" for a while and will finally shift into 4th, but does not go to lock up

I have moved the purple wire from the brake switch and hooked to the ground wire at the tail lights and with the brake on it has 12vdc at the purple wire
brake off no voltage at purple wire when if in off

P0741 is TCC lock up off

Re: 4L60E Torque Converter
 

So the engine and PCM are from a 2008?

Re: 4L60E Torque Converter
 

Not sure if its your problem or not, but could it be because the ECM is looking for an input speed sensor that the 2003 transmission doesn't have? Looking at the schematics for the two, that is the only obvious difference I see.

Re: 4L60E Torque Converter
 

I do have the VSS hooked up, are there different reluctors for a 2003 and a 2008>
4L60E?

Re: 4L60E Torque Converter
 

The VSS would be the output speed sensor. The 2008 transmission has an input speed sensor inside of it that the 2003 doesn't have. There are 15 wires on the big round plug on the newer one where as the older one only has 13, the other 2 are the ISS signal to the ECM. I'm only speculating though that that is the problem.

Re: 4L60E Torque Converter
 

Thanks
I will count the wires in the connector first
Check with the harness builder and then the trans shop
There is a VSS on the tail shaft and connected

Re: 4L60E Torque Converter
 

Well you may of hit on something
13 wires on the connector for the 2003 and the controller is a T 42 am I missing some
wires or is the controller "made" to be compatible with this trans?
I will ask the computer,programmer/harness builder

Re: 4L60E Torque Converter
 

In 2006 the internal harness was changed see attached files.

Re: 4L60E Torque Converter
 

Welcome from the cactus patch, and thanks for the answer

Thank you for the info,
Here is what the shop had to say

The 2003 does have the 13 pin and the Transmission program is already calibrated for the 13 pin transmission, so no, that is not the problem.

The PO741 code is specific to the TCC performance\stuck off.