TSB PIT6477C — Cadillac, Chevrolet and GMC Service bulletin
PIT6477C is a service bulletin on file with NHTSA for 5 Cadillac, Chevrolet and GMC models, 2021–2025 model years. A TSB is factory repair guidance, not a recall — the repair is not automatically free.
What the bulletin says. This preliminary PI was created to advise techniians in the field that they will not be able to perform a GDS automated bleed with the scan tool dues to a issue with the software in the scan tool
NHTSA's own summary of the document, quoted from the public manufacturer-communications file.
Vehicles and model years PIT6477C names
| Vehicle | Model years |
|---|---|
| Cadillac Escalade | 2021, 2022, 2023, 2024, 2025 |
| Chevrolet Silverado 1500 | 2022 |
| Chevrolet Suburban | 2021, 2022, 2023, 2024, 2025 |
| Chevrolet Tahoe | 2021, 2022, 2023, 2024 |
| GMC Yukon | 2021, 2022, 2023, 2024, 2025 |
Every document filed under PIT6477C
| Document ID | Filed | Type |
|---|---|---|
| PIT6477C | June 5, 2026 | Service bulletin |
Questions buyers ask
What is TSB PIT6477C?
PIT6477C is a service bulletin filed with NHTSA by Cadillac, Chevrolet and GMC, covering 5 Cadillac, Chevrolet and GMC models across the 2021–2025 model years. NHTSA's summary reads: This preliminary PI was created to advise techniians in the field that they will not be able to perform a GDS automated bleed with the scan tool dues to a issue with the software in the scan tool
Which vehicles does PIT6477C cover?
NHTSA's file names Cadillac Escalade (2021–2025); Chevrolet Silverado 1500 (2022); Chevrolet Suburban (2021–2025); Chevrolet Tahoe (2021–2024); GMC Yukon (2021–2025). 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 PIT6477C a recall, and is the repair free?
No. PIT6477C 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 PIT6477C?
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 PIT6477C, 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 PIT6477C. Check any specific vehicle's open recalls by VIN at nhtsa.gov/recalls.