Can't read the computer????

I have a 04 Taurus 3.0 OHV. The SES light is on and I tried to scan it at work with a Matco scanner. The scanner said that it was unable to connect to the computer, so I went to Autozone to have it scanned because they had done it in the past and it had worked, that didn't work either. I have been told that it was some kind of CAN thing with these cars so I made sure that the tool was capable of that which it was and still no dice. I have come to figure out that it is somewhere between the link in the car and computer. Does anyone know what to do to get this to work. The light is constantly on and the car is runnng really bad to the point where I have almost gotten hit the car loses power during accel in the middle of traffic almost like its running out of gas then it picks back up after a few seconds or longer each time. Thanks

You'll probably need to start by tracing the wires from the diagnostic connector to the PCM. Unfortunately, I don't have a factory service manual for the 2004 model year, so I can't look for likely suspects.

There should be a constant power source on pin 16 of the diagnostic connector as well as ground on pins 4 and 5. I'd suggest you check for power and ground to the connector. If you have good power and ground, then you are pretty much down to the serial communications differential bus (pins 2 and 10). The ISO bus (pin 7) is for the Generic Electronic Module and the remaining populated wire is for the EEPROM programming voltage (pin 13).

Pins 2 and 10 probably connect to the PCM on pins 16 and 15 respectively if the wiring for the 2004 is the same as the 2002 model year.

-Rod

I made sure the ground and constant power were good, which they are. So now what? Im no quite sure what the next step with the serial communications differential bus. There aren't any pins on 2 and 10.