TSB PIT6521 — Buick, Chevrolet and GMC Service bulletin
PIT6521 is a service bulletin on file with NHTSA for 4 Buick, Chevrolet and GMC models, 2023–2026 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.
What the bulletin says. This PI advises dealers that if DTC P0606 and/or P0607 are set in the K160 EBCM, additional diagnostic aids should be followed to ensure the module requires replacement
NHTSA's own summary of the document, quoted from the public manufacturer-communications file.
Vehicles and model years PIT6521 names
| Vehicle | Model years |
|---|---|
| Buick Enclave | 2025 |
| Chevrolet Colorado | 2023, 2024, 2025, 2026 |
| Chevrolet Traverse | 2024, 2025 |
| GMC Canyon | 2023, 2024, 2025, 2026 |
Every document filed under PIT6521
| Document ID | Filed | Type |
|---|---|---|
| PIT6521 | June 9, 2026 | Service bulletin |
Questions buyers ask
What is TSB PIT6521?
PIT6521 is a service bulletin filed with NHTSA by Buick, Chevrolet and GMC, covering 4 Buick, Chevrolet and GMC models across the 2023–2026 model years. NHTSA's summary reads: This PI advises dealers that if DTC P0606 and/or P0607 are set in the K160 EBCM, additional diagnostic aids should be followed to ensure the module requires replacement
Which vehicles does PIT6521 cover?
NHTSA's file names Buick Enclave (2025); Chevrolet Colorado (2023–2026); Chevrolet Traverse (2024–2025); GMC Canyon (2023–2026). 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 PIT6521 a recall, and is the repair free?
No. PIT6521 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 PIT6521?
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 PIT6521, 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 PIT6521. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.