[pjmoreland]

I hooked the Arduino controller up to my truck and spent some time today working on the code. After trying several different approaches, I was able to read the speed sensor reliably. I have to count the amount of time it takes for 8 pulses (one revolution) to be received. Trying to measure the time for one individual pulse was not consistent. I was also able to read the 4th gear switch, although the switch seems to be loose inside or something because it sends occasional brief signals when it is off, and especially when I drive over some bumps. I cleaned up that signal by reading the switch 10 times in a row and assuming it is off if any of the 10 readings say it's off. The signal is solid when it is on. I setup a simple speed-based control that locks the TCC in 4th and above 50mph, and then unlocks under 45mph. The logic works well and is consistent. I haven't worked on the vacuum sensor yet other than to verify I can read the signal.

I had a major setback on this project today though, unfortunately. Since the TCC was locking above 50mph without a vacuum switch to unlock it, I was able to give it more gas while locked than I have been able to before. That's when I discovered the TCC is slipping. I had been suspecting it was doing that previously, but I had assumed it was just the vacuum switch unlocking it. I dropped the transmission pan this afternoon and replaced the TCC solenoid, but it didn't make any difference. The old solenoid bench tested just fine. I guess this is when I find out if TCI honors their one year warranty on torque converters. I'm annoyed about having to drop my transmission.