TSB 9B1 — Hyundai Service campaign
9B1 is a service campaign on file with NHTSA for the Hyundai Sonata, 2020–2023 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.
What the bulletin says. The subject vehicles may have Diagnostic Trouble Code (DTC) P0451 stored in the ECU, which could cause the Check Engine Lamp to come on.
NHTSA's own summary of the document, quoted from the public manufacturer-communications file.
Worth checking your VIN against. 9B1 is filed as a service campaign, which unlike an ordinary bulletin can mean free or reimbursed work when a vehicle qualifies. Ask a dealer using the document ID below, and check open recalls separately at nhtsa.gov/recalls.
Vehicles and model years 9B1 names
| Vehicle | Model years |
|---|---|
| Hyundai Sonata | 2020, 2021, 2022, 2023 |
Every document filed under 9B1
| Document ID | Filed | Type |
|---|---|---|
| 9B1 OL | December 10, 2024 | Service campaign |
What 9B1 covers
Electrical — the component vocabulary NHTSA files this communication under.
Questions buyers ask
What is TSB 9B1?
9B1 is a service campaign filed with NHTSA by Hyundai, covering the Hyundai Sonata across the 2020–2023 model years. NHTSA's summary reads: The subject vehicles may have Diagnostic Trouble Code (DTC) P0451 stored in the ECU, which could cause the Check Engine Lamp to come on.
Which vehicles does 9B1 cover?
NHTSA's file names Hyundai Sonata (2020–2023). 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 9B1 a recall, and is the repair free?
9B1 is filed as a service campaign, not a recall — but this is the kind of communication that can mean free or reimbursed work if your VIN qualifies. Take the number to a dealer and ask. Recalls are separate and always free; check yours by VIN at nhtsa.gov/recalls.
How do I get the full text of 9B1?
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 9B1, 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 9B1. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.