'11 silverado, python 872

The 2011 Silverado should a Passkey3+ system which is a hybrid transponder and Passlock type setup. So not only is the ECU looking for the transponder code, it is looking for a change in voltage on the PL wire. The constant cranking is most likely the result of not getting the correct PL voltage. The PL wire voltage will vary according to the following: On keysense is +/- 12V On accessory is +/- 0V On ignition is +/- 4V On start is +/- 3V You can try to replicate these values with relays and resistors but it would be easier to use a module for this task. I have been using the OL-MDB-AL (ADS-AL-CA) or Fortin EVO-ALL whenever I encounter PK3+ systems. You can keep the TBxKey with XpressKey and not wire up the transponder portion of the ADS or Fortin modules as shown in the install guide.This information is provided only as a reference.

All circuits should be verified with a digital multi-meter prior to making any connections.

That makes sense. But why does it work when I use voltage sense instead of virtual tach? Also why does it only crank continuously on the third attempt per cycle? And why does it function perfectly if the vehicle is warm? It also appears that some people have used the tbxkey sucessfully on similar vehicles. I will try one of those modules you mention though and see how it works. Thank you for the input.

Did you ever get your truck to start? Also, I am thinking about installing power locks, mirrors, and windows in my 2011 WT. Can you tell me what kits, parts you used to do thisto your truck. I also want to put a remote start in. Thanks...

Wow, I just happened to check on my old post since I only recently found the time to work on the truck and somebody else had revived it. In short, no, I have not gotten the truck to start with the remote start. I picked up a Fortin Evo-All CANBUS module but all it does is make the truck think there is a key in the ignition all the time. Here is a link to the power window kit I bought from Amazon: http://www.amazon.com/Absolute-HW600-Power-Window-Conversion/dp/B004IX6798/ref=sr_1_2?ie=UTF8&qid=1369602854&sr=8-2&keywords=power+window+kit The switches fit right over the holes left by the cranks once you open up the holes a little. They could use more power though, the passenger side only works if the engine is running. Theres probably better kits out there. The locks I pieced together with a bunch of parts from eBay and stuff I had laying around. I thought about putting in power mirrors but I have the manual towing mirrors and they've been fine. And a word of advice, don't buy a factory refurbished Directed Electronics product. I'm pretty sure that's why I'm having all these problems with getting this thing to work.