Vehicle: 2014 Jeep Grand Cherokee, 4WD, V6 3.6L,
Problem: With a scan tool, the technician
checked activation status in the power lift gate module to see if
module was receiving a signal when a switch was pressed (handle
switch, interior switch or remote key fob). Yes, it was receiving
a signal to open from all inputs. He then checked in the body
control module (BCM) trunk release data and noticed that it was
switching from “pressed” to “not pressed” on its own – without
pressing a button (see BCM PID screen). Next, he unplugged all
the switches and the trunk release data revealed that it was
still switching in the BCM.
Details: The technician tested communication
with all of the modules and looked for diagnostic
trouble codes (DTCs). He found communication with the body
control module (BCM) to be intermittent and no DTCs were present.
After looking at the CAN B circuit diagram, he went to the fuse
block in the
Confirmed Repair: The technician opened the BCM
and found traces of water damage and some corrosion on the
circuit board. He replaced the BCM and the issue was resolved.