Tried to start the truck yesterday morning and it would not crank over. Checked batteries and they were good. Jumped the starter wire and the truck fired right up. When I tried to drive it, it would barely move. I believe that the only forward speed it has is 3rd gear. I also noticed that I have no reverse lights and the back-up aid sensors are not working. Seems like it could be as simple as a bad neutral safety switch, but I plugged in my Autoenginuity and it can't communicate with the TCM. I am getting code U0101- "Lost communication with TCM" and when I try to link directly to the TCM it say it cannot find it to communicate with. SO... any ideas would be very helpful and where is the TCM (next to driver side battery?) if so isn't this also the PCM? Where is the neutral safety switch located? (steering column or tranny)
This is the truck in my sig line.

Thanks-

Bump

 

Still no luck. Any ideas?

 

The TCM is in the same box as the PCM. They are next to driver's side battery.
The neutral safety switch is inside the trans.

 

Mark, thanks for the response. I just got done tearing apart the steering column of course only to find that the Neutral safety switch is not there. Inside the trans huh? bummer. Where at and how hard is it to get to? Have you ever run accross or heard of a problem like this before? It really reaks of a neutral safety switch but the fact that my scanner cannot communicate with the TCM really makes me want to head in that direction...

 

ok. the tcm is in fact part of the pcm. time to check fues first. from there its checking powers and grounds. not really my cup o'tea here. so not a lot I can offer with out a truck and a few books in front of me.
if I can help further just ask. feel free to drop me a pm.

 

I sure would. I think going into the trans now is a waste of time. You need to find out why the TCM is not communicating. That is almost certainly the root cause of your problem.

 

Ok, agreed. Having been a trans engineer, I'm sure you have had a lot of experience with these types of issues, where you you start in trying to isolate the communication problem?

 

look at the wiring diagram and check the network wires first. keep in mind if you are missing power or ground to the module you will also not be able to talk to it.

 

A sincere thanks to all who helped me with this problem. I pulled the fuse box and removed then re-installed all plugs from the back and then removed and re-installed all plugs from the PCM/TCM and everything began to work normally. I now have communication with the TCM and no codes are re-setting. I would highly recommend checking all connections when dealing with an electrical issue prior to assuking the worst.
Thanks again!

 

glad it was an easy deal.