I have a 2004 Chevy Silverado 2500HD 8.1 liter. At start-up the motor will start, ramp up to an appropriate RPM, then immediately fall on its face and stall. Typically when its cold, it seems to do a little better, but it will still come very close to stalling out. After it has ran for a while and warm it seems to do it more. Anybody have suggestions?

 

Id be willing to bet it is bad O2 sensors, have them checked.

 

Codes show:
B0055-vehicle speed sensor circuit
B0161-torque converter clutch brake switch circuit
U1300-class 2 data link low.

Anybody have any ideas on what could be the problem?

 

What scanner did you use? My definitions are:
B0055-2nd row center seat belt sensor
B0161-no definition
U1300-class 2 communication circuit high volts class 2 data output link low (suggests a short or bad ground)

B codes are body codes and shouldnt effect the engine operation, but a short or ground issue will/can cause an issue

 

Yea...thats what I have been finding. I think the guy told me the wrong definition for the B codes.
The U1300 is the one that I am focusing on. Any ideas on how to track down where the short is? Or make it right.

 

you can try plugging in your scanner and select diagnostic circuit test, class2 monitor. see if it can "see" all the modules." inactive " read should help you narrow down the affected harness