Circuit/System Testing

Ignition OFF, disconnect the harness connector at the following modules one at a time. After each disconnect, clear the DTC, cycle the ignition key 3 times, then test for the DTC. DTC U2099 should remain current.
- EBCM
- Transfer case control module
- If the DTC becomes history, replace the last module disconnected when the DTC became history.
Ignition OFF, disconnect the X3 harness connector at the BCM.
With the modules still disconnected, test for infinite resistance between BCM X3 terminal 19, and ground.
- If less than the specified value, test the circuit for a short to ground.
If all circuits test normal and the DTC is set as current, replace the BCM.