Transfer Case Will Not Complete A Mode or Range Shift

Transfer Case Will Not Complete a Mode or Range Shift

Test 1-6:

Circuit Description
The range/mode switch circuit consists of 4 normally open switches. The transfer case shift control module supplies a regulated 8 volts DC to the switch through the 8 volt reference circuit. The current travels through a 9.09 K ohms resistor located inside the switch, then returns current to the transfer case shift control module through the switch signal circuit.

When each of the switches is depressed, they complete a circuit through their own specific resistor. The transfer case shift control module continuously monitors the switch input to determine whether the 4HI, AUTO 4WD, 2HI, and 4LO button selections are made by the driver. NEUTRAL may be obtained if the following conditions are met:
^ The engine is running.
^ The automatic transmission is in NEUTRAL.
^ The vehicle speed is below 5 km/h (3 mph).
^ The transfer case is in the 2HI mode.

Once these conditions have been met, pressing and holding both the 2HI and 4LO buttons for 10 seconds will shift the transfer case into NEUTRAL, turning on the red NEUTRAL indicator lamp.

Test Description
The numbers refer to the step numbers on the diagnostic table.
2. This step tests the functionality of the mode/range buttons.
3. This step tests the ability of the modules to operate the transfer case modes.