Chevrolet Silverado 1500 2020–2022 — technical service bulletin
Bulletin N222375000 · NHTSA communication 10222263 · issued Oct 3, 2022
Technical service bulletin
communication type
Visibility
component
2020–2022
model years
6
vehicle entries
Official summary
In certain vehicles, equipped with a manual HVAC system (RPO: C4P), the K33 HVAC Control Module may not properly enable the heater auxiliary coolant pump to maintain cabin heater temperature during engine auto stop events. Reprogram the K33 HVAC Control Module with updated software.
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.