TransGo kit and resistor

greiswig · **Posted:** Mon Jul 14, 2008 12:51 pm

In another thread, it sounds as though a lot of people who have installed the TransGo kit have regretted having the pump pressure resistor installed because it made the 1-2 shift too hard. It's not clear to me whether all of these also had the Suncoast installed as well.

I'm putting in the Transgo kit, but for the time being I can't afford the Suncoast. I'd be curious as to whether others have done this with or without the resistor, and what their experience was. It would also be very easy for me to install a different value resistor...perhaps one that is somewhere between whatever the Transgo value is and the stock value of 0 ohms?

gmctd · **Posted:** Mon Jul 14, 2008 1:16 pm

545RFE Line Pressure output may be increased by adding an offset resistor - been intending to do this, but would rather drive my Dodge - 2k is the nominal value used in shift kits - a SPDT switch could be used to setup two resistors, one 2k for max, second 1.2k for towing, say - also could install a 2k linear taper pot for continuously variable pressure, set to your preferences, 0 to max - just hook the center tap to the trans signal line, either of the other two taps to the ECM signal line - I'd splice the offset into the signal wire at a point closest to the TCM so (a) - the splice is in the engine bay, not under the vehicle, and (b) - the wires into the in-cabin control are much shorter - make a twisted pair for RFI\EMI suppression.

The TCM has a "learn" mode - when the offset is installed, TCM has learned to shift at some previous pressures - it will take some time to learn to shift under the offset pressure, much like towing a trailer several days, then getting the harsh loaded shifts in an unloaded vehicle until TCM learns the load is gone - TCM should learn to lighten up after a while - point being, don't pre-judge the initial response - drive it a bit to allow TCM to learn - the gradual pressure increase afforded by the pot may be the ticket

Ripster · **Posted:** Mon Jul 14, 2008 1:36 pm

I don't tow too often and I do not have the suncoast. It was suggested by TransGo to remove the resistor to smooth up the 1 to 2nd shift.
Just could not get it to smooth out, removed the resistor, had tech reset the learn sequence at the dealer and back to smooth ever since.
I have the new pump, new TQ under warranty and the shift kit without the resistor. Has been the ticket so far, you can always add the resistor, plus splicing is one thing that I don't like doing, but did on install. GMCTD is correct and with the suncoast it may be great.
I just don't have a dealership I trust to do the learn sequence now.

gmctd · **Posted:** Mon Jul 14, 2008 1:58 pm

What interval did you run the resistor B4 having it removed and the relearn reset?

ATXKJ · **Posted:** Mon Jul 14, 2008 3:34 pm

I ran mine for a couple of weeks and then pulled the resistor.
I wasn't towing anything - and it never learned to calm down - always felt like I was powershifting without a clutch.

gmctd · **Posted:** Mon Jul 14, 2008 3:51 pm

Several members have mentioned that it takes quite awhile to settle back to normal after dropping the trailer - to get the final answer the resistor and TRS enable should prolly be next, as they're easier - was gonna measure Rail Pressure output with simple DVM, compare the 0-5v reading at the sensor with what ECM is seeing the other side of EDGE Trail offset, but the official Rail Pressure guage is due any day, now, so have been waiting out the heat and the mosquitos - 'nuther words, lazy...................

Ripster · **Posted:** Mon Jul 14, 2008 8:31 pm

GM, a couple of months, had to keep pressure on or accelerate through the shift, if it caught the shift at coast or barely
accelerating, very hard shift.

CATCRD · **Posted:** Mon Jul 14, 2008 8:53 pm

Ripster wrote:

GM, a couple of months, had to keep pressure on or accelerate through the shift, if it caught the shift at cost or barely
accelerating, very hard shift.

Same here. Took it out after a couple months. The 1-2 shift while accelerating very slowly in a parking lot was very hard. About every other 2-3 shift would be a balky double clunk. Moderate throttle shifts felt about normal, and full throttle shifts were ideal. Still are without the resistor, and the strangeness is gone.

gmctd · **Posted:** Mon Jul 14, 2008 9:53 pm

How about a "RACE" switch, sorta like a "TOW" switch or "OFF-ROAD" switch? Connect it to TCM pin30, flip it, and yer good to go firmly and quickly..........

greiswig · **Posted:** Mon Jul 14, 2008 10:44 pm

Good info, all. Has anyone tried a smaller value like gmctd suggested...around 1kohm?

fastRob · **Posted:** Tue Jul 15, 2008 9:06 am

ATXKJ wrote:

I ran mine for a couple of weeks and then pulled the resistor.
I wasn't towing anything - and it never learned to calm down - always felt like I was powershifting without a clutch.

Do you have a chip or software performance mods?

ATXKJ · **Posted:** Tue Jul 15, 2008 2:35 pm

fastRob wrote:

ATXKJ wrote:

I ran mine for a couple of weeks and then pulled the resistor.
I wasn't towing anything - and it never learned to calm down - always felt like I was powershifting without a clutch.

Do you have a chip or software performance mods?

Not yet...

TransGo kit and resistor

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