In code you can see this 2 lines:

int torqLock=1875;
int torqUnlock=1700;


1875 is frequency from speed sensor @ 65 KMH (Canada)
1700 is frequency from speed sensor @ 59 KMH

This are your 2 parameters for Lock/Unlock.

How I found them? Easy.... When truck is running (I used 2 jacks to lift it up)
in Arduino tools-serial monitor pop up window will show frequency. I ran truck at 65 kmh and found frequency... the same for unlock...

 

1. Speed sensor sends signal to op amp amplifier

2. Amplifier amplifies it and sends it to Arduino pin #5

3. Arduino keeps checking frequency from amplifier pin #5. As soon as frequency is higher than 1875 (different trucks can be different) it sends signal to pin#8.

4. Pin #8 connected to relay which Locks/Unlocks TC (just like manual switch)

5. Relay is kept Locked until frequency doesn't fall to 1700.

6. When frequency is 1700 Arduino unlocks relay and TC is unlocked.

 

Please post your comments about this solution. It is not perfect but much better than manual switch and cost only about $20+ time to build it.

I still use manual switch to override Arduino some times. Here is scenario when I use manual switch. I drive uphill in traffic or just hill is steep. As soon as I reach 65kmh TC locks but load is too high for this slow speed. I will turn switch off. The Arduino keeps locking TC but I manually broke the circuit with switch.

I use Arduino auto lock when I drive on flat surface empty or with light load.

Later I will add button or POT to make speed Lock adjustable on the fly.

Enjoy

 

Seems to me it would be much more trouble to also have that control O/D solenoid. Thoughts?

 

What do you want to do with solenoid and when? Just post more logic.... What do you want to control speed, rpm, acceleration etc? Arduino is very powerful device and can control many things....

I just used vehicle speed as a reference to lock/unlock. You can add TPS. I didn't try to outsmart manufacture, just replaced manual switch with a bit of logic....

 

Number of folks have been looking for solutions to trans control in things other than ram trucks. Various engine conversions, etc. One of the biggest stumbling blocks for putting the 46R? trans behind anything that doesn't have a computer, is controlling the trans. If O/D and TCC could be controlled with just a couple different inputs..... lots of folks would like that.

 

Can you be more specific? What inputs do you want to control? Arduino can use many different digital and analog inputs/signals than use your logic code and send signal to relay.

In my situation I didn't use ecu/obd. I used speed sensor directly. Speed sensor sends analog signal, then it is amplified/digitized with op-amp, then used to calculate frequency/speed.

 

I want to control (well, not me personally, but, others I have seen. ) TCC, and O/D. Inputs would be Vehicle speed, and engine load (tps?). Disable both until about 45 MPH. Then let 'em both go. Drop out of Overdrive at say, half throttle? drop out of tcc below 43mph.

 

I am not an electronic engineer or computer programmer. I had TC manual lock switch problem (forget to turn off when stop) I spent about a week searching what and how. This is my first Arduino project and I love it.

Now I have solution under $20 to lock/unlock TC when I want (65kmh-lock, 59-unlock) and the most important it doesn't forget to turn TC off below 59 kmh. Can it be improved? For sure add TPS, brake pedal signal, etc. But my goal was to make easy cheap solution to replace manual switch.

This project can be a good start point. To measure vehicle speed and get just a number in digital device is a real PITA which is now done. TPS is just a variable resistor and can be used as an analog input. To control solenoid or any other ON/OFF device you need to add relay and use one of the digital outputs to control it. Arduino is not a "buy this black box solution" you decide what to do and when and how....

My next Arduino project will be heating/ventilation control in my house. It will control when use outdoor air when recirculate air based on outdoor indoor and set point temperatures. It will turn on/off AC compressor, air blower, circulation pump for radiant floor heating etc.

I started lerning about Arduino here: