2002 Silverado 2500 HD Automatic Transmission problem

My gear gauge acted up first, only lighting up in R,3,2,1 not in P or in D.
When driving it feels like I am in second gear, When I downshift from drive the transmission does not react except for in reverse. Is this a problem with the transmission, or could it be a computer problem?
The truck has only 40,000 MI. I also have an after-market remote starter installed by professionals. Could it in some way be causing this problem? It was installed about eight months ago but this problem started today.
Any help would be appreciated.

Thank you
Rich

The auto start uses relays to shoot current to lines that are used to start the car.

But he could have removed some of the insulation on some of the wires trying to find the correct lines used to start the truck.

Most likely he man-handled everything and might have broke a few wires or the wires were put back in the wrong place and they are putting pressure on some eletronics which is causes malfuctions.

Take it back to the place and have them take a look. They should do it for free. They will fight tooth and nail to not pay for the damages but at least you will know if there is a problem.

Ask them where did they spliced the lines and have them show you.

Did they splice lines by the tranmission or in the cab?

If they give you a hard time, in a calm voice as for their names and position and tell them that you will be contacting the manufacture of the starting system. That is about all you can do.

That is why I hate alarm places. They can do what they want and not have to worry about anything. Cartoys in Irving, TX has been the only place that I have found that was a little honest.

Can you explain more about the tranmission. I really do not understand.

If you are driving and you change from D to 2 it does not go into 2?

Try this.

1. Drive the truck about 10 feet.
2. Put the shifter in N
3. Turn the key off.
4. Try to restart the truck.

Does it start?
If so then the gear selector part is working.

Also:

Stop using the Auto start for a few days and see if the problem continues. (Take the fuse out for the auto start) They can tell you where the fuse it at when you have them take a look at everything.

When I am driving, I can't go over 50mph without pushing 4,000 rpms. At 40mph, if I downshift to 3rd or 2nd or even 1st, it doesn't change gears. The transmission seems to be stuck in 2nd gear, maybe 3rd but no higher. When I take off from a stop, I feel it change gear one time but not again. I read a post in another forum that had a similar issue but did not list 02 Silverado as included. It stated that the ignition switch has a relation to the transmission and that the transmission may be being forced to stay in 2nd gear "a safe gear" as a result of some switch related to the transmission, not getting the proper amount of energy or possibly shorting out when a remote starter is installed. Like I said, 02 Silverado was not included in this post and I am curious if anyone had heard anything similar.
I will try your suggestions and get back to this thread tomorrow. And the remote starter was purchased and installed at Fred Schmits, a large chain electronics store.
Thank you for your help.

I called a local Chevy dealer today and talked to a tech, he said it is probably the shift solenoid. I don't know jack about electronic transmissions and the truck is still under waranty so I guess I will take it in and get it looked at tomorow and spend the $200 on my deductible, can't afford it now, but I can't afford to be without a truck. I will let you know what they find.
PS
It will start in neutral and taking the fuse out of the autostart doesn't make a differance

I am glad it is not the auto-start be a real pain to fix.

There have been a few strange TPS on these tranmissions.

I am glad it is not the auto-start be a real pain to fix.

There have been a few strange TPS on these tranmissions.
Don't be so sure. If for some reason the remote starter is not energizing the 2nd ignition wire(white wire) it will cause transmission failure. On the newer trucks you can shut the truck down and restart it with the key to correct this problem but some of the older trucks this will not work. It basically causes the transmission to self destruct :newburn:
Yes, I know this because I own a shop specializing in remote starters.

I always knew those auto-starters were bad news. They is why I keep away from them.

The hardware might be full proof but the installer ????

Well, guys, I was off the mark about the auto-starter.
After taking my truck to one of the local Chevy dealers for diagnostic check, the codes came back as "P0708 & P0722, CK RANGE SWITCH OPERATION- WOULD GO OPEN, REPLACE SWITCH, CK RESISTANCE OF VSS- WAS LOW, REPLACE VSS SENSOR."
They replaced the Range Selector Switch and the Vehical Speed Sensor Switch. The truck seems to be opperating fine now.
Without the extended warranty this would have cost about $550.00
Sorry about assuming it was the auto-starter, it was something I read and I guess I just jumped to conclusion. The tech at Chevy, told me he had heard of no such problems.