Here is a procedure for obtaining trouble codes from the transfer case control module. This would be a necessary step in further diagnosis, to see if there are any codes stored.
Obtaining Diagnostic Trouble Codes
The diagnostic trouble codes are displayed on the three transfer case shift select buttons. The shift select buttons are located on the instrument panel when the connector pin 13 on the data link cable is grounded, and the ignition switch has been OFF for at least five seconds prior to positioning the ignition switch to run the shift select buttons will blink various times together in order to indicate a diagnostic trouble code from 1 to 4.
1.1. Position the ignition switch to OFF.
Ensure the ignition switch is positioned to OFF for at least 6 seconds.
1.2. Connect pin 13 on the data link cable to a vehicle ground source.
The data link connector is located in the cab under the instrument panel on the drivers side.
1.3. Position the ignition switch to RUN.
1.4. Note the shift select buttons for blinking codes. Refer to Diagnostic Trouble Codes. See: Diagnostic Trouble Code Tests and Associated Procedures NVG 243-NP1 (Two Speed Selectable) Diagnostic Trouble Codes
If the shift select buttons all blink one time and stop, and do not continue to blink, no fault codes are stored in the TCCM.
The transfer case shift select buttons will blink in order to identify any stored DTC. If only one code is stored in the TCCM memory, that code will blink repeatedly with a three second delay between blinking sequences. If more than one code is stored, the first code will blink once, then after a three seconds delay, the next code will blink. This sequence will continue until pin 13 is no longer grounded.
When reading the diagnostic trouble codes, the number of shift select buttons blinks will indicate the code number.
Sunday, February 27th, 2011 AT 8:14 AM