This should help you with LFC 4 5 .............
U: LFC 45/DTC U2018 - Passenger Side Crash Sensor Comm. Fault
Normal Operation
The passenger side crash sensor monitors the severity of a crash event. If the crash event is severe enough, the sensor will signal the Restraints Control Module (RCM) to deploy the passenger side air bag.
The RCM monitors the two-wire current loop to the passenger side crash sensor for a signal that is out of the expected range. If the RCM detects an out-of-range signal from the passenger side crash sensor, indicating a sensor communication fault, it will store Diagnostic Trouble Code (DTC) U2018 and flash a Lamp Fault Code (LFC) 45 (or a higher priority code if one exists) on the air bag indicator.
Possible Causes
A passenger side crash sensor communication fault condition can be caused by:
damaged wiring on circuit 1263 (WH).
damaged wiring on circuit 1264 (BN).
damaged passenger side crash sensor.
