21-NA-049
Service Bulletin Details
Public Details for: 21-NA-049
This service bulletin provides a diagnostic aid for picoscope information and setup for transmission related concerns.
Models from 2023
2023 CHEVROLET CORVETTE |
Models from 2022
2022 CHEVROLET CORVETTE |
Models from 2021
2021 CHEVROLET CORVETTE |
Models from 2020
2020 CHEVROLET CORVETTE |
Bulletin No.: Service Bulletin Date: 21-NA-049 August, 2022 INFORMATION Subject: Diagnostic Aid – PicoScope Information and Setup for Transmission Related Concerns Brand: Model: Chevrolet Corvette Model Year: VIN: from to from to 2020 2023 — — Engine: Transmission: All Automatic (M1M) Involved Region or Country North America, Europe, Middle East, Japan Information This document provides information related to the CH-51450 PicoScope NV tool, set up, recording, and sound file submission to the GM Technical Assistance Center (TAC) for noise type concerns within the transmission. Information Service Procedure Note: Ensure you are using a PicoScope purchased through the GM dealer tool network. PicoScopes purchased outside of the GM dealer tool network have different software, which will corrupt the file. Note: For additional training and information on PicoScope, visit the Center of Learning and search for course PicoScope Noise, Vibration, and Harshness Diagnostics Overview and Oscilloscope Diagnostic Kit Description and Operation within SI. If you need to download or update the PicoScope, follow the steps below: 1. Log into GM GlobalConnect. 2. Click on the "Departments" drop down menu and select "Service.” 3. Under "Applications" on the service page, select "Special Tools and Software updates.” 4. You will now be re-directed to www.gmtoolsandequipment.com (do not access this site directly as it requires the use of GlobalConnect to allow downloads). 5. Click the link under "Software Downloads" for the latest PicoScope software version and a new page will open. 6. Click the setup links and follow instructions to update the tool. Copyright 2022 General Motors LLC. All Rights Reserved. 5751814 1. Place the PicoScope sensor on the bolt head shown in the image above. This is located on the right side of the transmission, near the transmission cooler. This bolt is used to secure a bracket for the wire harness. The sensor cable can be run into the passenger compartment with the engine compartment closed. Note: Ensure to keep the cable routed away from the exhaust. Page 2 August, 2022 5751815 2. Open the most current version of GM NVH. Bulletin No.: 21-NA-049 5751818 3. After completing the wizard, go back into the setup tab under Vibration Signal and select Single Channel. Select TA148 Interface in the “Box” dropdown and TA144 Microphone for the “Sensor” Drop down. Select the Location as Engine Compartment. Set the Diff Ratio to 3.55. Note: If using 3 axis, use center channel only and set up as single axis. 4. Drive the vehicle to verify condition and record a Pico data file of the concern. 5751816 5751819 5. While the reviewed file is on the screen, click File Save. It should be formatted as .pddata Bulletin No.: 21-NA-049 August, 2022 Page 3 5751820 6. The next box allows you to save the vehicle information as well as customer information and notes in the Notes box. This could be sensor location, sensor direction and even road surface name, etc. Click Ok when you are done adding information. 7. If PICO scope data shows readings under 85 decibels, vehicle noise is deemed as a normal characteristic. 8. Create an e-mail to [email protected] in the U.S. and [email protected] in Canada and in the subject line Put Vibration, your BAC, and last 8 of the VIN. Note: For Middle East, Japan or other countries, contact your local TAC for submission instructions. Parts Information No parts are required for this repair. Version 2 Modified Released March 04, 2021 Revised July 29, 2022 – Added the 2022 and 2023 Model Years, Transmission RPO M1M, Europe to the Involved Region or Country section and step 7. GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information. WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION