# Service bulletin 21\-NA\-214

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: 10242114
- Published by NHTSA: 2023\-09\-09
- Manufacturer's number: 21\-NA\-214
- Manufacturer's date: 2023\-08\-10
- NHTSA component: SERVICE BRAKES, AIR; ELECTRICAL SYSTEM; POWER TRAIN; ENGINE AND ENGINE COOLING

## NHTSA's summary

This technical bulletin provides repair information to correct a customer concern of Service Engine Soon Lamp being illuminated. They may also comment on multiple transmission issues including harsh or delayed shifts, slip, surge, shudder, noise, whine, growl, shake and/or vibration. As well as the exhaust brake not working or that they do not feel it. Technicians may find DTCs P2002, P2463, P2459, P144E, P0421, P0422, P0106 P20EE, P129F, P16F3, P20FF, P226D, P249D, P249E, P11CC and / or P11D5.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2023/MC-10242114-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2023/MC-10242114-9999.pdf)

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

## Components

Brakes, Electrical system, Engine, Transmission and driveline

## Trouble codes named

P0106, P0421, P0422, P11CC, P11D5, P129F, P144E, P16F3, P2002, P20EE, P20FF, P226D, P2459, P2463, P249D, P249E

## Vehicles listed

- 2020 CHEVROLET SILVERADO 2500
- 2020 CHEVROLET SILVERADO 3500
- 2020 GMC SIERRA 2500
- 2020 GMC SIERRA 3500

## Recalls for the same vehicles and component

- [2026060](/recalls/tc/2026060.md), 2026-02-12: Powertrain
- [26V083000](/recalls/nhtsa/26V083000.md), 2026-02-12: POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE; POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY
- [25V768000](/recalls/nhtsa/25V768000.md), 2025-11-06: SERVICE BRAKES, HYDRAULIC:POWER ASSIST
- [25V390000](/recalls/nhtsa/25V390000.md), 2025-06-12: SERVICE BRAKES, HYDRAULIC:BRAKE FLUID LOW WARNING:SWITCH/SENSOR/FLOAT
- [2024637](/recalls/tc/2024637.md), 2024-10-24: Powertrain
- [24V797000](/recalls/nhtsa/24V797000.md), 2024-10-24: POWER TRAIN:AUTOMATIC TRANSMISSION:FLUID/LUBRICANT:VALVES/VALVE BODY; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE:SOFTWARE
- [2020505](/recalls/tc/2020505.md), 2020-10-23: Powertrain
- [20V650000](/recalls/nhtsa/20V650000.md), 2020-10-22: POWER TRAIN:DRIVELINE:DRIVESHAFT
- [2020079](/recalls/tc/2020079.md), 2020-02-27: Brakes
- [20V116000](/recalls/nhtsa/20V116000.md), 2020-02-27: SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DISC:CALIPER

## Other bulletins for the same vehicles and component

- [N252515590](/bulletins/11027795.md), 2026-01-27, Service campaign: ELECTRICAL SYSTEM. Certain vehicles listed above, may have a condition in which the body\-to\-chassis ground strap may be corroded. Dealers will replace the ground strap.
- [24\-NA\-262](/bulletins/11026024.md), 2025-12-03, Service bulletin: POWER TRAIN. This bulletin helps aid the tech in possible 10L100 transmission noise that may be normal or abnormal depending on the concern noted.
- [00\-06\-01\-026R](/bulletins/11026017.md), 2025-12-03, Service bulletin: ENGINE. This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
- [23\-NA\-170](/bulletins/11024486.md), 2025-10-25, Service bulletin: ELECTRICAL SYSTEM; ENGINE. This bulletin advises the tech to inspect deeper into what may be to main cause of an engine failure.
- [23\-NA\-153](/bulletins/11024485.md), 2025-10-25, Service bulletin: ENGINE. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
- [23\-NA\-201](/bulletins/11024378.md), 2025-10-21, Service bulletin: SERVICE BRAKES; ELECTRICAL SYSTEM; STEERING. This service bulletin advises the technician of a possible loose ground that may be causing customer concerns of Loss of Steering Assist and/or Loss of Brake Assist and Malfunction Indicator Lamp \(MIL\) Illuminated.
- [24\-NA\-241](/bulletins/11024332.md), 2025-10-16, Service bulletin: ENGINE. This informational bulletin advises the technician of a part number change for long block engines used in the trucks noted.
- [22\-NA\-080](/bulletins/11024330.md), 2025-10-16, Service bulletin: ENGINE. This technical bulletin provides a procedure to replace the camshaft actuator magnet to correct customer concerns of engine related shudder.
- [N242454441 \-03](/bulletins/11024189.md), 2025-10-09, Service campaign: POWER TRAIN. Certain vehicles listed above, may have a condition where the transmission control valve has worn, resulting in a gradual loss of pressure within the valve. The effects can cause harsh shifting, setting a service engine soon message, reduced engine performance or P0747 diagnostic trouble code. Dealers are to install a new control valve body. The repairs will be made at no charge to the customer.
- [22\-NA\-161](/bulletins/11023368.md), 2025-09-27, Service bulletin: ELECTRICAL SYSTEM; VISIBILITY/WIPER. This informational bulletin provides information for dealers/technicians on power folding mirrors do not fold at the same speed.

JSON: [/v1/bulletins/10242114](/v1/bulletins/10242114)

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