TSB 21-NA-124 — Chevrolet Service bulletin
21-NA-124 is a service bulletin on file with NHTSA for 2 Chevrolet models, 2000–2002 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.
What the bulletin says. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
NHTSA's own summary of the document, quoted from the public manufacturer-communications file.
Vehicles and model years 21-NA-124 names
| Vehicle | Model years |
|---|---|
| Chevrolet Cobalt | 2000, 2002 |
| Chevrolet Trailblazer | 2000 |
Every document filed under 21-NA-124
| Document ID | Filed | Type |
|---|---|---|
| 21-NA-124 | December 14, 2022 | Service bulletin |
What 21-NA-124 covers
Engine — the component vocabulary NHTSA files this communication under.
Questions buyers ask
What is TSB 21-NA-124?
21-NA-124 is a service bulletin filed with NHTSA by Chevrolet, covering 2 Chevrolet models across the 2000–2002 model years. NHTSA's summary reads: This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set.
Which vehicles does 21-NA-124 cover?
NHTSA's file names Chevrolet Cobalt (2000, 2002); Chevrolet Trailblazer (2000). A bulletin number can be re-issued against more vehicles later, so check the model-year list on this page against your own.
Is TSB 21-NA-124 a recall, and is the repair free?
No. 21-NA-124 is repair guidance the manufacturer sent its dealers, not a safety defect finding. You pay for the work unless the vehicle is still under warranty. Recall repairs, by contrast, are always free.
How do I get the full text of 21-NA-124?
Take the document ID to a dealer's service desk, or search NHTSA's manufacturer-communications records. This page carries every document ID filed under 21-NA-124, its date, and NHTSA's own summary from the public file.
Every number on this page is a count of records in the federal complaint, recall, and investigation files published by NHTSA's Office of Defects Investigation. This page lists only what NHTSA's manufacturer-communications file records under 21-NA-124. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.