okay to start i changed my transmission on Saturday and it seems to be slipping in o/d. Now the check engine light came on yesterday so i called a local tranny shop and asked them for possible solutions. They told me the cel could be on due to the transmission.Now i plugged in a scan tool not sure of the type but it will not read anything on my truck. Its a 2000 f150 4x4 5.4 so we plugged it into a 99 150 and everything came up fine. Also tried it on other vehicles and all was good but no reading on my truck. Anyone have any ideas why it won't read my truck

 

You have a fuse out.

 

I'll check that out but would that stop it from reading?

 

I am having the same problem. I checked all the fuses and relays in the truck and under the hood. I have a scan tool i bought at auto zone, not the cheap one either. I am at a total loss right now. I even have an old wiring harness that I unrapped looking for possible issues --- nothing found. Please help. Thanks.

 

Plug tool in, put key into on position. nothing?

 

It's the same fuse as your cigarette lighter. Try the lighter and see what happens.

 

Fuse#3, Cigarette Lighter/Data Port Connector are on the same fuse!

My Daughters Cavalier had the OBDII, Cig lighter, and Horn on the same fuse, she had a short in the horn.