OK first locate the TCCM (transfer case control module) then unplug it and check for any corrosion. If it looks good then I need you to reconnect it and check for voltage at Term C4 with key on engine off see first pic below. The TCCM is under the dash attached to the steering column support bracket. I would also like you to check for codes that the tccm may have stored. To do this make a jumper wire to put between the Orange wire (term 13) and ground. Now turn key on engine off and count the lights on the 4x4 switch. Once key is on in about 3 seconds it will blink codes and if there is more then 1 code it will have a 3 second delay between codes. Once all codes are read it will restart at the first code. See second pic below for how to count the light blinks for the codes ok. Now once all codes are retrieved I would like you to turn key off and clear the codes. To do this after key is off remove the T-Case fuse from the fuse box for at least 3 minutes. Then reinstall the fuse and turn the key on and off 5 times. Let me know what you find.
TCCM Connector
How to count for codes.
Friday, January 29th, 2010 AT 10:17 AM