Nothing Happens (Dead System)

Electronic Shift Transfer Case Schematic:

The obvious first step in diagnosing a dead system is to check the POWER SOURCES, FUSES AND GROUNDS. If these check out, perform the Shift Control Module Diagnostic Test. The illustration shows the Module with pigtail A, B and C attachments. The Diagnostic Test button and Diagnostic Test LED are located on the side of the Shift Control Module.
1. DISCONNECT the B and C connectors, turn ON the ignition and allow 4 seconds for the Module to power up.
2. Then PUSH the Diagnostic Test button.
a. If the LED doesn't illuminate, the Module is dead and must be replaced.
b. If the LED comes on and stays on for 30 seconds, there is an error condition and the module will have to be replaced.
c. If the module is OK the LED will flash 4 times.
This test, however, is not 100 percent accurate. During the test, the vehicle isn't operating, so the Shift Control Module isn't receiving data and initiating shifts. If the unit passes the Diagnostic Test, it's probably a good Module. Check for other probable causes, although the Module may need to be replaced even after passing the Diagnostic Test.