Chevrolet Avalanche 1500 2007 — technical service bulletin
Bulletin 070419001 · NHTSA communication 10022472 · issued Jun 1, 2007
Technical service bulletin
communication type
Power Train
component
2007
model years
7
vehicle entries
Official summary
Intermittent/inoperative four wheel drive, service 4wd system lamp on and dtc c0378 - front axle switch circuit signal invalid. *kb
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.