Problem: The vehicle was towed in and the
customer said it will not start.
Details: After the tech verified the problem, he
connected a scan tool and reported that he could not communicate
with the PCM or TCM. The scan tool would communicate with the air
bag and body control modules. Next, he tested for battery voltage
at Pin 29, connector C1 at the PCM (red wire). He found 0 volts.
The power should have come from fuse 23, circuit A919 in the
Totally Integrated Power Module (TIPM).
He applied B+ power to that circuit at Pin 29 on the PCM and the
truck started and ran normally.
Confirmed Repair: The tech found and repaired
the broken red wire between the TIPM connector C1, pin 13 and the
PCM connector C1, pin 29. After the repairs, the engine started
and ran normally.