What wire would I tap at the tcm
for a TCC indicator light, I would like to know when TCC is engaged.
Its not a true necessity but just something I wouldn't mind monitoring.
I have one on old blue's 700r4 and it was a piece of cake.
not so sure on the alli though.
Merle

Pins 32 and 29 at the TCM are the battery and ground sides of the TCC solenoid, respectively.

I will provide information on this one so you don't damage the driver in the TCM.

First off...pin 32 is 12volts with the key on.

Second....the low side driver (pin 29) is PWM so it would not drive any conventional bulb.

Here is the one that will bite you. The low side driver is monitored using a voltage drop so if you attach anything that draws current to the wire...a code will set and the driver will turn off.

I suppose a LED could be used but it would flash at a high frequency.

Hope this helps.

Why is this so complicated? on my 700r4 12 volt is applied to a selonoid which opens the port for clutch apply.
Selonoid is internally grounded.
Does not the alli do the same thing? its not a modulated apply its applied or not applied same as the old 700r4 is it not.
I know on some of the later ecm controled 4l460's 12 volt was constant at the selonoid and engagement was controled by the ecm taking it to ground.
which if the alli was the same a simple relay would work a indicator bulb.
am i all wet here or is the alli really that complicated.
The part that confuses is that the TCC selonoid has to have a solid 12 volt and an equal solid ground in order to operate doesn't it?
Thanks, Merle

Why is this so complicated? on my 700r4 12 volt is applied to a selonoid which opens the port for clutch apply.
Selonoid is internally grounded.
Does not the alli do the same thing? its not a modulated apply its applied or not applied same as the old 700r4 is it not.
I know on some of the later ecm controled 4l460's 12 volt was constant at the selonoid and engagement was controled by the ecm taking it to ground.
which if the alli was the same a simple relay would work a indicator bulb.
am i all wet here or is the alli really that complicated.
The part that confuses is that the TCC selonoid has to have a solid 12 volt and an equal solid ground in order to operate doesn't it?
Thanks, Merle

Tap into that baby and watch the christmas lights go on.):h You are trying to compare 26 year old tech to the Ally.

Use a 12 volt LED in series with a high Ohm resistor (probably 1 Meg or more) across 32 and 29. It will be flashing with TCC lock up, but as such a high rate you will percieve it as just being dim. At full lock (full duty cycle) it will be bright. So you will get a visual indication of the lockup as it happens. Off to Dim to bright.

The LED only requires milliamps to run and the solenoid amps, so the TCM will not notice the minor draw through the resistor. Remember, the LED has a polarity to it.

Thanks Fingers for not being a smart a$$, in reading between the lines I take it that the TCC is not as the oldies either on or off, apparently it does have a modulated apply by electronic means.
I can understand that and that was the point of the question.
I already took down the christmas tree.
Thanks, Merle

do you have to used both of them? 32 and 29? if not which one is needed if there is a seperate power source?

You could just use 29. 32 is basically just ignition power.