4x4 will not engage changed actuater, and tested switch on transfer case
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2000 GMC Sierra 1500 Question: 4x4 willnot engage
Answer #1Visitor, February 25, 2011, 05:16
The Transfer Case Control Module (TCCM) has not received the wake-up call during key-up and has remained in the "sleep mode".
When the TCCM is in the "sleep mode", it will not communicate with the class II bus or the Tech 2�.
Try to communicate with the TCCM. If no communication, go to step 2. If communication is possible,
go to step 5.
Remove the underhood (ATCM or TREC) TCCM fuse.
Wait 30 seconds.
Reinstall the fuse. The module should "wake up" and communicate with the Tech 2�.