Technical Service Bulletin 20NA166 — 2018 GMC SIERRA 2500
ENGINE AND ENGINE COOLING
Bulletin Details
| TSB ID | 20NA166 |
| Manufacturer | |
| Vehicle | 2018 GMC SIERRA 2500 |
| Component | ENGINE AND ENGINE COOLING |
| Communication Date |
Bulletin Summary
This informational bulletin advises the technician of possible coolant entering the areas of the engine, either through failed parts or defects in the castings, that may be the cause of the concerns related to the MIL or the engine running rough.
About Technical Service Bulletins
A Technical Service Bulletin (TSB) is a document issued by a vehicle manufacturer to its dealers, describing a known issue with a specific vehicle or set of vehicles and the recommended procedure to fix it. Unlike recalls, TSBs are not mandatory and are typically only performed if an owner reports the related issue. However, TSBs can be an indicator of common problems with a vehicle.