Honda Fit 2015–2020 — technical service bulletin
Bulletin A21010B · NHTSA communication 10186011 · issued Jan 18, 2021
Technical service bulletin
communication type
Fuel System, Gasoline
component
2015–2020
model years
6
vehicle entries
Official summary
"ServiceNews Article - If normal troubleshooting suggests replacing the fuel injectors, check the long-term fuel trim using the i-HDS to ensure that it's fixed right the first time. -If it is less than 1.0% (lean), then it's most likely caused by the injectors. -If it is more than 1.0% (rich), then it's most likely caused by carbon buildup on the valves. Use a commercially available valve cleaner to resolve the carbon issue."
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.