Chevrolet Avalanche 2003–2004 — technical service bulletin
Bulletin 01267F · NHTSA communication 10007624 · issued Jan 1, 2004
Technical service bulletin
communication type
Electrical System
component
2003–2004
model years
12
vehicle entries
Official summary
Service 4wd light on no codes besides u1000 codes or c0550. *mj
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.