Problem: Vehicle was towed in to the shop for a
no-start condition ever since the vehicle was jump-started from
another vehicle. According to the vehicle owner, the battery was
not jumped backwards. There was no flash and no arching marks
visible on the battery terminals.
Details: The technician retrieved 35 diagnostic
trouble codes (DTCs) of all different types from many different
modules. There was also a burned smell in the vehicle. The tech
noticed that the gauges and lights in the instrument cluster
would not work with the key in the “On” position. Since the
“wake-up” signal for the instrument cluster comes from the body
control module (BCM) through the data line, he decided to check
the BCM first. After verifying that power and grounds to the BCM
were all were within specifications, he opened the BCM cover.
Confirmed Repair: Under the cover, the problem
was clear. The circuit board was badly burned. The technician
reprogrammed a used BCM as a replacement. The issue was resolved.