TSB: CADILLAC ESCALADE, SIERRA 1500, SILVERADO 2500, SUBURBAN, TAHOE, YUKON (2015–2016)
Bulletin GCUS-3-804 — January 5, 2017
Bulletin Details
| Bulletin ID | GCUS-3-804 |
| Manufacturer | CADILLAC |
| Models | ESCALADE, SIERRA 1500, SILVERADO 2500, SUBURBAN, TAHOE, YUKON |
| Model Years | 2015–2016 |
| Date Issued | January 5, 2017 |
| Date Added to NHTSA | April 2, 2018 |
| Component | ELECTRICAL SYSTEM |
| Vehicles Affected | 8 combinations |
What is a TSB?
A Technical Service Bulletin is a document issued by the vehicle manufacturer to inform dealership technicians about a known issue and the recommended repair procedure. TSBs are not mandatory recalls — they serve as repair guidance for common problems.
If your vehicle has this issue, bring this bulletin ID to your dealer. If under warranty, the repair should be covered at no cost.
Summary
28770 - SUB A ?Service 4WD? message may be displayed on the Driver Information Center and DTC C0398 may be set. Concurrently, the vehicle is permanently locked in 4HI and cannot be shifted shift out of it while the code is present. If the
Affected Vehicles
| Make | Model | Year | Component |
|---|---|---|---|
| CADILLAC | ESCALADE | 2016 | 110000 ELECTRICAL SYSTEM |
| GMC | SIERRA 1500 | 2016 | 110000 ELECTRICAL SYSTEM |
| CHEVROLET | SILVERADO 2500 | 2016 | 110000 ELECTRICAL SYSTEM |
| CHEVROLET | SUBURBAN | 2016 | 110000 ELECTRICAL SYSTEM |
| CHEVROLET | TAHOE | 2016 | 110000 ELECTRICAL SYSTEM |
| GMC | YUKON | 2016 | 110000 ELECTRICAL SYSTEM |
| GMC | SIERRA 1500 | 2015 | 110000 ELECTRICAL SYSTEM |
| CHEVROLET | SILVERADO 2500 | 2015 | 110000 ELECTRICAL SYSTEM |
Related CADILLAC Recalls
What Should You Do?
If your vehicle is affected by this TSB, contact your authorized CADILLAC dealer. Bring this bulletin ID (GCUS-3-804) when you visit. If under warranty, the repair should be free. If your warranty has expired, ask about goodwill coverage — manufacturers sometimes cover TSB-related repairs beyond the warranty period.
Frequently Asked Questions
A recall is a mandatory safety fix — the manufacturer must repair every affected vehicle for free. A TSB is an advisory document that describes a known issue and the recommended fix, but repairs are not required. However, some TSBs eventually lead to recalls if the issue poses a safety risk. TSBs are generally issued for quality or performance problems, while recalls address safety defects.
If your vehicle is still under the manufacturer's warranty, TSB-related repairs are typically covered at no cost. If your warranty has expired, you can ask the dealer about goodwill or customer assistance programs. Many manufacturers will cover or partially cover repairs for well-known issues, especially if the TSB was issued recently or affects a large number of vehicles.
Check the make, model, and model year listed above against your vehicle. If they match, this bulletin likely applies. However, TSBs may only affect vehicles with specific production dates, VIN ranges, or configurations. Your dealer can confirm by entering your VIN into their service system, which will show all applicable TSBs and recalls.
This data comes from the National Highway Traffic Safety Administration (NHTSA). Manufacturers are required to submit copies of all communications (including TSBs) sent to their dealers to NHTSA. The agency makes this data publicly available as part of its vehicle safety monitoring program.