Making the ECT button useful

[ZackR]

Overdrive is controlled by engine coolant temp and not trans temp. I made this error in the past but was corrected.

 

[80t0ylc]

Did this mod the other day, great to be able to turn off the ECT (power mode) at will when in low range, when the power mode is off it makes the shifts from 1st to 2nd really smooth when moving really slow in low. It's pretty easy to do. Thanks to the OP.
Cheers

Couple of questions. My '94 FSM shows the TCM behind DS kick panel. Was this where you found the module? Also, 1st post by @ThreeEyedBandit (who can also reply to these questions) in this thread mentions the pins modified are on connector 'B'. The schematics in the back of my FSM show the pins to be in connector 'C'. Looks like according to the schematic pic of the connectors, there's 2 connectors - 'C' and 'D' that plug into the bottom of the TCM. The larger 22 pin connector 'C', and a smaller 12 pin connector 'D'. Does this sound like the animal that gets modified?

This is a pic of the TCM connector pinouts in my FSM and you can see how they're labeled:

Thanks in advance for your help!

 

[ThreeEyedBandit]

My 94 FSM shows that it is on the B connector, post a picture of each page of the EWD and we'll get this sorted.

Also, my TCM was under the steering column, not what I would call the kick panel.

 

[80t0ylc]

My 94 FSM shows that it is on the B connector, post a picture of each page of the EWD and we'll get this sorted.

Also, my TCM was under the steering column, not what I would call the kick panel.

This is the full page in my FSM concerning the TCM

This page is in the AT (automatic trans) section and shows the approximate position of the TCM

Hope this helps. I haven't tried the mod yet, but expect to soon, weather allowing...lol
Thanks for posting this thread!

 

[ThreeEyedBandit]

Resolution is not good enough for me to zoom in, try a couple different pictures with more detail.

 

[80t0ylc]

Sorry, try these:

 

[ThreeEyedBandit]

Yup! You will use connector C. Which is the same as my connector B. Not sure why my PDF versions show it being different, but its the same connector and location.

 

[Jasonazx]

Hey @ThreeEyedBandit wanting to perform this mod on my 97. I saw your post regarding instructions for my year, so once I get to the module I should have no issues. Do you or anyone else know exactly where the tcm is located on my year?

Edit: One more question… when in high range I always have the ect on for better acceleration. Will I lose the normal operation/function of this button performing this mod? For example, if I press the button to have it in pwr mode as usual, the mapping would change to the low range mapping hard shifts while in high range? I saw in another one of your posts you showing how to keep it in pwr mode all the time. Does this mean it would function like I have it now when in high range, with the option to select it into the low range mapping when pressing the button? Can you elaborate on this a bit and explain how this would be done on my 97?

Thank you!

 

[ThreeEyedBandit]

Your TCM is part of the ECU, I would have to find a FSM to figure out where thy put it for sure.

Correct, now the switch controls the map selection entirely. Button on, low range map in either high or low range and button off is high range map in either. You will loose the functionality of the ECT switch's factory function.

 

[60 toy ota]

So in other words it does for the shift points the same thing that cdl switch + pin 7 does for the center lock, putting 100% of the operation in the switch itself

 

[ThreeEyedBandit]

So in other words it does for the shift points the same thing that cdl switch + pin 7 does for the center lock, putting 100% of the operation in the switch itself

Correct

 

[Jasonazx]

Your TCM is part of the ECU, I would have to find a FSM to figure out where thy put it for sure.

Correct, now the switch controls the map selection entirely. Button on, low range map in either high or low range and button off is high range map in either. You will loose the functionality of the ECT switch's factory function.

Got it, thanks! Is there anyway to retain the factory function of the ect modes, especially in high range?

 

[ThreeEyedBandit]

Got it, thanks! Is there anyway to retain the factory function of the ect modes, especially in high range?

Simply without adding a second switch, no. You can hard wire it to always be on or off easily. I might look at the EWD to see how difficult it would be to tie into the H/L switch.

 

[Jasonazx]

Simply without adding a second switch, no. You can hard wire it to always be on or off easily. I might look at the EWD to see how difficult it would be to tie into the H/L switch.

That would be ideal to have it on all the time, and then select the mapping manually with the switch. Thanks for your help!

 

[Drift Monkey]

Simply without adding a second switch, no. You can hard wire it to always be on or off easily. I might look at the EWD to see how difficult it would be to tie into the H/L switch.

Just digging around and it seems like the yellow wire in this thread connects to the 4L position switch that switches the transmission mapping from H to L - disconnecting it seems to keep it in H mapping since it never gets the signal back from the transfer case that it’s now in L. Seems like you could trace this line and put a switch on it if you wanted H mapping while shifted into L.

I’m not sure how you’d reverse it if you wanted L mapping in H though, or how this would wire into the ECT switch. Just an idea for someone who wanted this functionality for whatever reason.

 

[ThreeEyedBandit]

Here is a couple garbage videos kind of demonstrating the differences. Similar throttle used, can get the shift to be even lower with a little load and no traffic.

All in low range-

High range map, ETC off


Low range map, ETC on


Both done in low range