Chevrolet Avalanche 2012–2013 — technical service bulletin
Bulletin PIE-0225-B · NHTSA communication 10047919 · issued Oct 1, 2012
Technical service bulletin
communication type
Power Train
component
2012–2013
model years
13
vehicle entries
Official summary
Chevrolet/gmc: the 4wd fails to engage when service 4wd indicator illuminates and transfer case control module (tccm) reports possible c0379 set. Models 2012-2013 avalanche, silverado, suburban, tahoe, sierra, yukon, yukon xl. *pe
Vehicles covered
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.