No crank issue with ITBC plugged in

WhitetailCrazy

New member
May 20, 2011
4
0
1
Illinois
2014 Silverado 2500HD LML. No crank issue. No line under the “P” park indicator and the fuel gauge bounces. This unit is deleted and tuned. Previous owner says that he hit a pothole and the gauges went erratic. Drove truck home, shut it off and went to restart it and he had the no crank issue. Plugged in the EFI programmer that came in the delete kit to check for codes and noticed that the gauges stop bouncing when the programmer is plugged in. Tried to start it and it did start. He ran it with the programmer plugged in for a long time. I am not OK doing this so I dug into it to find the real issue. In troubleshooting and by accident I found that unplugging the ITBC module will get the truck to start. Pulling the ITBC fuse will as well. All the gauges settle out and the line under the P shows up. With a Tech 2 I can clear all of the codes and the only one left that won’t clear is the U0137 for the trailer brake when I have the ITBC fuse out. Put the fuse back in and get loss of communication / communication erratic codes for all the main modules as well as the U0137. Traction control, ABS, stabile track or whatever flashing etc. The tech 2 never connects to the TBCM ( trailer brake control module). Without doing any more troubleshooting I replaced the ITBC module. No change. I have been all down the wiring harness pulling and twisting it while someone watches the dash looking for any change but have not seen any. I think I know what the issue is but want to see if anyone has experienced this before and can give me a better idea where to look and what to look for.


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