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Anthony, Chevy Technician
Category: Chevy
Satisfied Customers: 11808
Experience:  GM Certified
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I have a 2011 chevy silverado 3500 6.6 diesel dualy and have

Customer Question

I have a 2011 chevy silverado 3500 6.6 diesel dualy and have around 89000 miles on it... i need help with the tcm problem just came up the other day...before there was no problem at all. its a well maintained truck. never had any problem before..i just started my truck and about to leave for work 2 days ago,..when i put the shifter into drive i felt something going weird.. i had the check engine lights is on. i attempt to drive to see if it is able to drive or not and then i notice that its just stuck in one gear and not able to go over 35 mph.. then i came back and parked it to my drive way and the shifter was hard to shift and making wierd noise. so i connected my snap on scanner and i found out that there is 8 different codes are showing ... the first one was UO101 which is lost communication with tcm and the others were all the glow plugs which is not cause the problem that i pretty much sure it is the TCM problem only.. so i took it to the dealer to reprogram the tcm, which is the cheapest way to start. so they tried to reprogram it several times but it did not work and they want to replace the tcm... it will cost me 1200$ if i get it replace and its not guaranted if it get fixed... so i need to know before i spend that much money is there anything else cause this ?... because even yesterday the truck went normal everything was fine and this morning i tried it one more time , at the first mile i drove was fine until i stop at the traffic light .when i attempt to move i notice that the problem just came back and couldnt go no more than 35mph.. so i really need to get this problem to be fixed.. pls help me with this problem.. tnx...
Submitted: 2 years ago.
Category: Chevy
Expert:  Anthony replied 2 years ago.


Its very common for the TCM to go bad and you get a U0101 code. If it wont program it has to be bad. I have a lot of experience with this problem.

Customer: replied 2 years ago.
what if i get it replaced and the problem still on what else should i have to look for...
Expert:  Anthony replied 2 years ago.

Severed wiring which will take a lot of time. Here's the preliminary tests that should have been done:

1. Verify power and ground to the TCM.

2. Verify 12 volts on the Dk Blue wire at pin 43, this is a "Wake-up" signal that has to present when the key is in the "ACCY and On" positions.

3. Verify a good connection at the TCM.

4. If OK, replace the TCM. Programming is required after installation.

Expert:  Anthony replied 2 years ago.

If the preliminary tests were done then it has to be the TCM.