# Service bulletin 20\-NA\-100

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: 10242265
- Published by NHTSA: 2023\-09\-15
- Manufacturer's number: 20\-NA\-100
- Manufacturer's date: 2023\-08\-30
- NHTSA component: ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM

## NHTSA's summary

This informational bulletin provides information for dealers/technicians on Engine Control Module Calibration for T1 L3B Engine with DTC P26BB Set.

## The document

- [NHTSA's copy of the document (PDF)](https://static.nhtsa.gov/odi/tsbs/2023/MC-10242265-0001.pdf)
- [If that address does not open, try this one](https://static.nhtsa.gov/odi/tsbs/2023/MC-10242265-9999.pdf)

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

## Components

Electrical system, Engine

## Trouble codes named

P26BB

## Vehicles listed

- 2019 to 2020 CHEVROLET SILVERADO 1500
- 2019 to 2020 GMC SIERRA 1500

## Recalls for the same vehicles and component

- [21V346000](/recalls/nhtsa/21V346000.md), 2021-05-13: ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE \(ECU/ECM\):SOFTWARE
- [2019631](/recalls/tc/2019631.md), 2019-12-12: Electrical
- [19V888000](/recalls/nhtsa/19V888000.md), 2019-12-12: ELECTRICAL SYSTEM:12V/24V/48V BATTERY:CABLES
- [19V328000](/recalls/nhtsa/19V328000.md), 2019-04-25: ENGINE

## Other bulletins for the same vehicles and component

- [N262576260](/bulletins/11038468.md), 2026-10-15, Service campaign: ENGINE. General Motors has decided to conduct a Voluntary Emission Recall. Certain vehicles may have a condition that could cause a small exhaust leak at the catalytic converter inlet. Dealers are to replace the catalytic converter inlet clamp and to inspect the catalytic converter – replacing it if damage is observed. The repairs will be made at no charge to the customer.
- [N262548050](/bulletins/11031551.md), 2026-04-24, Service bulletin: ENGINE. This message is to inform dealers that Special Coverage N262548050 is being temporarily suspended for the models above. Involved vehicles will be temporarily removed from IVH. Dealers will be notified when repairs can be resumed. We apologize for any inconvenience this situation may cause.
- [N262548050](/bulletins/11031510.md), 2026-04-23, Service campaign: ENGINE. Certain vehicles, may have a condition that could cause the Catalytic Converter to fail. If this failure occurs, the Malfunction Indicator Light \(Check Engine Light\) will illuminate, and a diagnostic trouble code will set. Dealers are to replace the Catalytic Converter as necessary. The repairs will be made at no charge to the customer.
- [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.
- [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.

JSON: [/v1/bulletins/10242265](/v1/bulletins/10242265)

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