LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2020 >> Corvette 2D Convertible >> Repair and Diagnosis >> Quick Lookups >> Technical Bulletins >> Campaigns >> Transmission Control Systems >> N202316880 - Transmission Control Module (TCM) Software Error/Mismatch (N202316880)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

N202316880 - Transmission Control Module (TCM) Software Error/Mismatch (N202316880)

Publication date: 2020-11-12
Reference number: N202316880

N202316880 - TRANSMISSION CONTROL MODULE (TCM) SOFTWARE ERROR/MISMATCH

N202316880 - TRANSMISSION CONTROL MODULE (TCM) SOFTWARE ERROR/MISMATCH

SERVICE CAMPAIGN BULLETIN

Reference Number(s): N202316880, Date of Issue:  Nov 12, 2020
Affected Model(s): 2020 Chevrolet Corvette

SERVICE INFORMATION

Release Date:  November 2020 Revision:  00
Attention:  This service update includes vehicles in dealer inventory and customer vehicles that return to the dealership for any reason. This bulletin will expire at the end of the involved vehicle's New Vehicle Limited Warranty period.
Involved vehicles will be repaired either through dealer repairs as described in this bulletin or through over the air (OTA) programming. Dealers can and should perform the procedure in this bulletin on any vehicle with an "open" status on the Investigate Vehicle History (IVH) screen in GM Global Warranty Management system. Due to the fact that vehicles will be closed in IVH through successful OTA programming, dealers should always check the status in IVH before performing any vehicle repairs  .
Make  Model  Model Year  RPO  Description 
From  To 
Chevrolet Corvette 2020 2020    

Involved vehicles are marked "open" on the Investigate Vehicle History screen in GM Global Warranty Management system. This site should always be checked to confirm vehicle involvement prior to beginning any required inspections and/or repairs.

Condition  Certain 2020 model year Chevrolet Corvette vehicles may have a condition where diagnostic trouble codes (DTC's) P1967 and/or P1968 may falsely set in the transmission control module (TCM) due to an internal software misalignment.
Correction  GM will update the software in the TCM. Owners who have accepted applicable terms and conditions will have the opportunity to accept these software changes using wireless over-the-air (OTA) technology without having to bring their vehicle to a dealership. Alternatively, owners may have their vehicle serviced at a GM dealer to receive these software updates.

PARTS INFORMATION

No parts are required for this repair.

WARRANTY INFORMATION

SERVICE INFORMATION

Labor Operation  Description  Labor Time  Trans. Type  Net Item 
9105265* Verified Module Software or Calibration Level: Module Is Programmed with Same Level Software or Calibration 0.2 ZFAT N/A
9105266* Transmission Control Module Reprogramming with SPS 0.5
IMPORTANT:

* To avoid warranty transaction rejections, carefully read and follow the instructions below:

  • The Warranty Claim Code must be accurately entered in the "Warranty Claim Code" field of the transaction.
  • When more than one Warranty Claim Code is generated for a programming event, it is required to document all Warranty Claim Codes in the "Correction" field on the job card. Dealers must also enter one of the codes in the "Warranty Claim Code" field of the transaction, otherwise the transaction will reject. It is best practice to enter the FINAL code provided by SPS/SPS2.

WARRANTY CLAIM CODE INFORMATION RETRIEVAL

If the Warranty Claim Code was not recorded on the Job Card, the code can be retrieved in the SPS system as follows:

  1. Open TLC/TIS on the computer used to program the vehicle.
  2. Select and start SPS/SPS2.
  3. Select Settings.
  4. Select the Warranty Claim Code tab.

The VIN, Warranty Claim Code and Date/Time will be listed on a roster of recent programming events. If the code is retrievable, dealers should resubmit the transaction making sure to include the code in the SPS Warranty Claim Code field.

SERVICE PROCEDURE

CAUTION:

Before downloading the update files, be sure the computer is connected to the internet through a network cable (hardwired). DO NOT DOWNLOAD or install the files wirelessly. If there is an interruption during programming, programming failure or control module damage may occur.

NOTE:

Carefully read and follow the instructions below.

  • Ensure the programming tool is equipped with the latest software and is securely connected to the data link connector. If there is an interruption during programming, programming failure or control module damage may occur.
  • Stable battery voltage is critical during programming. Any fluctuation, spiking, over voltage or loss of voltage will interrupt programming. Install a GM Authorized Programming Support Tool to maintain system voltage. Refer to www.gmdesolutions.com  for further information. If not available, connect a fully charged 12 V jumper or booster pack disconnected from the AC voltage supply. DO NOT connect a battery charger.
  • Ensure the ignition is turned OFF, load on the vehicle's battery such as; interior lights, exterior lights (including daytime running lights), HVAC, etc. may affect the download process.
  • Clear DTCs after programming is complete. Clearing powertrain DTCs will set the Inspection/Maintenance (I/M) system status indicators to NO.
GM5644477Courtesy of GENERAL MOTORS COMPANY
GM5431207Courtesy of GENERAL MOTORS COMPANY
IMPORTANT:

Techline Connect and TIS2WEB screens shown above.

IMPORTANT:

If the same calibration/software warning is noted on the TLC or SPS Summary screen, select OK and follow screen instructions. After a successful programming event, the WCC is located in the Service Programming System dialogue box of the SPS Summary screen. No further action is required. Refer to the Warranty section of the bulletin.

IMPORTANT:

When programming a module in GM's new Vehicle Intelligence Platform, or VIP, the power mode (ignition) needs to be off or errors may occur. This involves the 2020 Chevrolet Corvette, Cadillac CT5 and CT4, as well as the upcoming full-size Chevrolet, GMC, Cadillac SUVs and Buick Envision. Serial Data Message Authentication also needs to have the ignition off.

  1. Reprogram the Transmission Control Module. Refer to K71 Transmission Control Module: Programming and Setup   in SI.
    GM5644478Courtesy of GENERAL MOTORS COMPANY
    GM5431209Courtesy of GENERAL MOTORS COMPANY
    IMPORTANT:

    To avoid warranty transaction rejections, you MUST record the warranty claim code provided on the Warranty Claim Code (WCC) screen shown above on the job card. Refer to callout 1 above for the location of the WCC on the screen.

  2. Record SPS Warranty Claim Code on job card for warranty transaction submission.

DEALER RESPONSIBILITY

Whenever a vehicle subject to this service update enters your vehicle inventory, or is in your facility for service in the future, and the vehicle is still covered under the New Vehicle Limited Warranty, you must take the steps necessary to be sure the service update correction has been made before selling or releasing the vehicle.

All new, used, GM Certified Used, courtesy transportation vehicles, dealer shuttle vehicles, etc. in dealers' possession and subject to this bulletin must  be held and inspected/repaired per the service procedure of this bulletin before  customers take possession of these vehicles. Involved vehicles must be held and not delivered to customers, dealer-traded, released to auction, used for demonstration, or any other purpose.

All GM Certified Used vehicles currently in the dealers' inventory within the Certified Pre-Owned Inventory System (CPOIS) will be de-certified and must be held and remedied per the service procedure in this bulletin. Upon submitting an accepted/paid warranty transaction in the Global Warranty Management (GWM) system, the vehicle can be re-certified for sale within the CPOIS system, or once again be used in the CTP program.

DEALER REPORTS

The Inventory tab of the Open Vehicle Report will contain Service Update Bulletin VINs that apply to this field action. This information is intended to assist dealers with the PROMPT COMPLETION  of these vehicles. The Customer In-Service tab will not contain Service Update Bulletin VIN data because the intent of a Service Update Bulletin is to not inconvenience a customer with a special trip for service. Service Update Bulletins are to be completed when the customer is in for a regularly scheduled visit.