No Commincation wih OBD2 Scanner

Hello everyone!

Got a 2000 Toyota Tacoma SR5 3.4L 4x4 Manual. I love it. Unfortunately since the day I got it, I have not been able to pass NJ inspection not because of emissions (she passed emissions easily) but because no one could get the vehicle to link up to a OBD2 scanner. At first I did not believe them and figured their scanner was to blame and not the truck. I went out and borrowed an innovo 3130C scanner from autozone and guess what? It worked and I saw all the live data/all monitors were ready/no codes. I even did the alternator test on there just for kicks and again no problems. Took it to the inspection station the next day and failed again due to the same problem. Went home, pulled out the scanner and again it was working HOWEVER after that day I could never get it to connect to any scanner again. I tried the innovo, a harbor freight one, and even a snap-on solus...nothing. Then I tried to find a bad wire and found that all 4 of the wires were good. They all had continuity and I was getting power at pin 16. I noticed it always gets stuck at "detecting CAN" at 96% link progress. It detects various iso9141 stuff. So i figured the ECU/ECM/PCM went bad on it. Just to be sure I took it to a trusted mechanic and he concurred the same and quoted me $1375 including getting the ecu reprogrammed (i guess to match VIN#'s or something). That was way too much money to me so I sent mine out to get rebuilt for $150+ shipping. I ended up getting refunded minus shipping because the guy said he could not fix it or get it to communicate. Then I bought a "new" refurbished unit from autoecmstore.com with matching part numbers and everything for $500. It came in this morning, the truck started right up (although the old ecu started and drove fine as well). I still cannot get the scanner to communicate with the truck. Is this because the battery was disconnected? Do I have to do drive cycles just for the scanner to communicate? I don't think that's the case because even if the emissions systems were not ready, it should be able to connect.Is it possible I got a bad ecu unit? I checked for and cleaned corrosion, made sure the pins at the port were all the way in, checked the two ecu fuses in the cabin drivers side, checked the OBD2 fuse in the engine bay and everything checks out with the multimeter as far as continuity. All the interior lights work, the cigarette lighter port works. What am I missing?? It is driving me crazy having seen with my own two eyes a working scanner for two days and then boom never again. What do you experts think? Perhaps a ground problem? If so can anyone list all the grounds to check that might cause an issue like this? The truck has been off the road for a month now and I miss it.

Thank you

 

No luck yet ??

 

Unfortunately no but I did get it "passed" by inspections. I noticed that my tail light sometimes works and sometimes does not and also the airbag light goes on and off as it pleases. Looks like this truck has got several electrical issues...