# Service bulletin 21\-NA\-181

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

- Type: Service bulletin
- NHTSA id: 11011904
- Published by NHTSA: 2024\-12\-18
- Manufacturer's number: 21\-NA\-181
- Manufacturer's date: 2024\-11\-18
- NHTSA component: POWER TRAIN

## NHTSA's summary

This service bulletin provides 9th gear operation information to respond to customers that may comment on transmission shift operation.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2024/MC-11011904-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2024/MC-11011904-9999.pdf)

The document is the manufacturer's. This site does not hold it.

## Components

Transmission and driveline

## Vehicles listed

- 2020 to 2025 BUICK ENCORE GX
- 2021 to 2025 BUICK ENVISION
- 2019 to 2025 CADILLAC XT4
- 2020 to 2025 CADILLAC XT5
- 2020 to 2025 CADILLAC XT6
- 2020 to 2025 CHEVROLET BLAZER
- 2021 to 2025 CHEVROLET TRAILBLAZER
- 2020 to 2023 GMC ACADIA
- 2018 to 2024 GMC TERRAIN

## Recalls for the same vehicles and component

- [2023142](/recalls/tc/2023142.md), 2023-03-16: Powertrain
- [23V172000](/recalls/nhtsa/23V172000.md), 2023-03-16: POWER TRAIN:AUTOMATIC TRANSMISSION
- [23V043000](/recalls/nhtsa/23V043000.md), 2023-02-02: POWER TRAIN:DRIVELINE:DRIVESHAFT
- [23V042000](/recalls/nhtsa/23V042000.md), 2023-02-02: POWER TRAIN:DRIVELINE:DRIVESHAFT
- [2020520](/recalls/tc/2020520.md), 2020-10-29: Powertrain
- [20V668000](/recalls/nhtsa/20V668000.md), 2020-10-29: POWER TRAIN:AUTOMATIC TRANSMISSION
- [17V516000](/recalls/nhtsa/17V516000.md), 2017-08-22: POWER TRAIN:DRIVELINE:DRIVESHAFT

## Other bulletins for the same vehicles and component

- [N252502891\-01](/bulletins/11036308.md), 2026-08-20, Service campaign: POWER TRAIN. Certain vehicles may have a condition in which the internal differential nut was cross threaded or missing during assembly. Dealers will review the vehicles service history in IVH, and if necessary, replace the rear electric drive transmission module.
- [N252502890\-01](/bulletins/11036307.md), 2026-08-20, Service campaign: POWER TRAIN. Certain vehicles may have a condition in which the internal differential nut was cross threaded or missing during assembly. Dealers will review the vehicles service history in IVH, and if necessary, replace the front electric drive transmission module.
- [N242471460\-01](/bulletins/11036306.md), 2026-08-20, Service campaign: POWER TRAIN. Certain vehicles may have been built with an Electric Drive Unit mounting bolt that is too long, causing damage to the Drive Unit case. Dealers will inspect and replace the Electrical Drive Unit if necessary.
- [23\-NA\-119](/bulletins/11024331.md), 2025-10-16, Service bulletin: ELECTRICAL SYSTEM; POWER TRAIN. This service bulletin provides service procedure information to correct a customer concern of Shift to Park Displayed on DIC When Vehicle is in\- Park, No Start \- DTC B000A Set.
- [PI0281L](/bulletins/11019516.md), 2025-06-12, Service bulletin: STEERING; POWER TRAIN; SUSPENSION. This preliminary informational \(PI\) bulletin provides information to dealership personnel that may be helpful when addressing underbody component corrosion with customers.
- [25\-NA\-001](/bulletins/11016963.md), 2025-04-14, Service bulletin: POWER TRAIN. This service bulletin provides repair information to correct a customer concern of a transmission fluid leak.
- [19\-NA\-200](/bulletins/11016943.md), 2025-04-10, Service bulletin: ELECTRICAL SYSTEM; POWER TRAIN. This service bulletin provides a repair procedure to correct a customer concern of start/stop inoperative, MIL illuminated w/DTC P2797.
- [PIP6036A](/bulletins/11016668.md), 2025-04-07, Service bulletin: POWER TRAIN. This Preliminary information communicates diagnostic aids for a surge or fishbite concern
- [25\-NA\-001](/bulletins/11015623.md), 2025-03-14, Service bulletin: POWER TRAIN. This service bulletin provides repair information to correct a customer concern of a transmission fluid leak.
- [PIP5981D](/bulletins/11014631.md), 2025-03-02, Service bulletin: FUEL/PROPULSION SYSTEM; POWER TRAIN. This Preliminary information communicates ordering process for the front and rear drive units are on restriction for all listed EV vehicles for engineering review.

JSON: [/v1/bulletins/11011904](/v1/bulletins/11011904)

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