2023

Identifying Non-GM ECM Calibration Use and Power-up Hardware Detection in Duramax Diesel Engines Using GDS 2 – 2019-2023 Cadillac Chevrolet GMC

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General Motors

NHTSA ID Number: 10222660 Manufacturer Communication Number: 20-NA-090 Summary This informational bulletin provides a way for the technician to identify if the ECM has been modified.   General Motors Position on Aftermarket Power-Up Devices General Motors does not support or endorse the use of devices or modifications that when installed, increase the engine horsepower and torque. This … Read more

LIN Bus Diagnostic Information – 2014-2023 Buick Cadillac Chevrolet GMC

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Chevrolet Buick GMC Cadillac

NHTSA ID Number: 10224304 Manufacturer Communication Number: PIT5698C Summary This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus.   Condition As more smart motors, switches, and sensors are being used there are more Local Interconnect Network (LIN) buses on vehicles. Because of this, some questions … Read more

Avoiding Torque Converter Or Crankshaft Damage While Diagnosing Noise Concerns Do Not Separate The Torque Converter From the Flex Plate – GM Passenger Cars and Trucks

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General Motors

NHTSA ID Number: 10220319 Manufacturer Communication Number: 22-NA-181 Summary This diagnostic tip advises the tech not to separate the flexplate from the torque convertor or damage my occur if the engine is started while diagnosing for noise from the engine or transmission.   Condition Some customers may comment on a noise coming from underneath the vehicle equipped … Read more

Diesel Fuel System Contamination, Malfunction Indicator Lamp (MIL) Illuminated – DTC P026D, P2A00, P0171, P0172 and/or P0300 Set – 2017-2023 Cadillac Chevrolet GMC

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Chevrolet GMC Cadillac

NHTSA ID Number: 10222658 Manufacturer Communication Number: 18-NA-361 Summary This technical bulletin provides a procedure to flush the cooler lines to validate if there is excessive debris in the fuel system caused by a failed part.   Condition Some customers may comment that the MIL is illuminated.   Note: If removing the fuel filter from the filter … Read more

6.6L Duramax Possible Oil Leak Path Information – 2017-2023 Chevrolet Silverado & GMC Sierra

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2020 Chevrolet Silverado

NHTSA ID Number: 10222657 Manufacturer Communication Number: 18-NA-150 Summary This informational bulletin provides information on 6.6L Duramax Possible Oil Leak Path Information.   This document is to help identify where to look for an oil leak on the 6.6 Duramax engine. Note: Please keep in mind that a leak on the top of the engine will trail … Read more