We have a new Mack GU713  Vin# 1M2AX04C3CM010891 that we have  a  murphy model pv-101 remote model installed at a dealer and we have a problem with the idle dropping out. After looking we noticed that the dealer had cut the can-bus wires coming from the j19 plug and used but-conectors and straighted the can-bus wires.We think this is are problem because they didnt pin from the ECM. Do you have any ideas of what could cause the remote dropping out? 

i am not too familiar with newer model Macks, but on the older models you needed to tie into the circuit for the cruise control. The switch, that controls  throttle down may be bad

Check the speed sensor on the transmission.

Open the cover on the pass side and check the cruise control connection! The wire leadind to the cruise control comes loose! I think you can look at the underside of the cover plate and it will have the schematic!