Expedition 4WD V8-4.6L SOHC VIN W (1999)
P1830 - P1834: Testing and Inspection
P1834 is an information code (there is no testing for this code).
Code Description: Transmission Transfer Case Differential Lock-Up Solenoid Short Circuit to Battery.
Refer to wiring diagrams to diagnose this circuit, See: Transmission and Drivetrain/Transfer Case/Diagrams
For complete Transfer Case diagnostic information, See: Transmission and Drivetrain/Transfer Case/Testing and Inspection