I have had a lot of problems with a 1994 3vze mt 4x4 fed / canadian emissions truck. lets go backwards, the ecu is bad, after many parts, wiring repair and actually opening the ecu its toasted. Question is I ordered a new ecu, part numbers match serial number match, its a exact match however when I connect it in the truck and re-connect the battery the service engine soon light comes on, without the ignition being turned on. Also the truck will not start, this is supposed to be a good ecu. The truck will turn over, but will not fire. Do the used ecu have to be reprogrammed or something or is it bad.

I can start the truck with old ecu, and it will run until the motor warms up and then the problems start and it dies. It happens when the truck comes out of the closed loop.

 

I have also replaced the following on the truck after finding the parts bad.
transfer case
Spark plugs and wires
Distributor-signal Generator checked bad
replacedTPS - checked bad
numerous vaccum lines
O2 sensor
put catayatic convertor back on.
Ignitor, and coil
Fan and clutch
installed thermostat
removed and cleaned throttlebody
checked AFM
replaced engine ground strap
replaced starter
replaced VSM
replaced wiring from engine fuse box to the battery
read the wiring from TPS, knock sensor, temp sensor, cold start switch, fuel pump, coil, ignitor, distributor, AFM, O2 sensor to the ecu all checked good.
I think I'm missing a few.

 

I called Toyota, and verified my new used ECU is bad, now I have to send it back and find myself another one. I really want to get this truck back on the road or off the road should I say