Chevrolet Colorado 2004–2005 — technical service bulletin
Bulletin 040138012 · NHTSA communication 10012724 · issued Nov 1, 2004
Technical service bulletin
communication type
Equipment
component
2004–2005
model years
4
vehicle entries
Official summary
Whistle hiss hum noise heard when ac is on. *eh updated *eh
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.