2020 Corvette: Service Update: #N202319660: Service Update - Valve Spring Failure - (Nov 20, 2020)

#N202319660: Service Update - Valve Spring Failure - (Nov 20, 2020)

This service update should be performed on vehicles in dealer inventory only. 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.

Parts Information

Note: Use the VIN and the GM Electronic Parts Catalog (EPC) to determine which engine oil and filter to use for the oil change.

Reminder: Parts may be removed from Retail Inventory Management (RIM). Dealers should review the affected parts to confirm RIM managed status. Parts may have quantity limiters in effect.

Warranty Information

* The amount identified in “Net Item” should represent the actual sum total of the current GMCC&A Dealer net price for gasoline needed to perform the required repairs, not to exceed $51 USD, $66.72 CAD. This amount is not to exceed half a tank of premium gasoline per vehicle.

Inspection Procedure

1. Ensure vehicle has a ½ tank of fuel minimum.
2. Set vehicle up in a secure area where it cannot be stolen, with adequate ventilation (use exhaust vent hose if indoors) and open the hood or engine compartment lid. Keep vehicle away from any flammable surroundings or substances. Ensure the A/C is off. Finally, position a box fan blowing at the vehicle’s radiator.

• For Corvette Convertible, remove the folding top stowage compartment lid. Refer to Folding Top Stowage Compartment Lid Replacement in SI. Then, pause the convertible top halfway up, and position a box fan blowing down into the engine compartment. Be sure the area around the coolant reservoir is getting adequate airflow.
• For Corvette Coupe, position a box fan blowing down into the engine compartment. Be sure the area around the coolant reservoir is getting adequate airflow.
• For Manual Transmission equipped vehicles, be sure the vehicle has the parking brake engaged, the vehicles wheels are chocked, and the transmission is in neutral before performing the following steps.

Apply the brake and start the vehicle, holding the Engine Start/Stop button for at least 15 seconds.

• At this point, C8 Corvettes and T1 SUVs will display an “Automatic Shutdown Disabled” message on the DIC.
• Other vehicles will not display this message on the DIC, but by holding the Engine Start/Stop button for 15 seconds, the feature will still be activated on T1 Trucks and Camaros.

Set up your laptop in the vehicle, plugging the charging cable into the vehicle’s 110v power plug (or use an extension cord if the vehicle is not so equipped), and the MDI 2 into the vehicle’s OBDII port.

Open Techline Connect and navigate through GDS2.

• Select K20 Engine Control Module > Control Functions > Engine Speed/Throttle > Engine Speed.
• Drag the slider to the right until the engine’s idle speed is set to 2,000 RPM.

Using your phone or a timer you can keep near you, set a timer for 4 hours and 30 minutes and allow the vehicle to run.

Check on the vehicle at a minimum of 25-minute intervals to ensure it is still running, and run down the below checklist – the more often you can check on it, the better. The checklist includes:

• Normal Engine Operating Temperature
• No abnormal valve train noise
• No check engine light (especially P0300 or P030X)
• No abnormal burning smells (catalytic converter break-in smell is normal operation).
• Look underneath the vehicle and ensure there are no leaks.

If for some reason the vehicle does shut off during the test, restart it per the original instructions and continue the test from the time point where the vehicle shut off. It is not necessary to restart the entire test.

If any of these conditions are detected, immediately stop the test, immediately call the GM Technical Assistance Center for further instructions. For U.S. Dealers contact 877-446-8227. For Canadian Dealers contact 800-263-7740 (English) or 800-263-7960 (French). For International Dealers, if any of these conditions are detected, follow normal diagnostic and parts ordering procedures.

If 4.5 hours passes and none of these conditions are detected, replace any removed components and take the vehicle for a 10 mile test drive. Ensure the computer and MDI remain in the vehicle during this test drive so you can check DTCs if necessary. Utilize manual shifting mode for the entire duration of the test drive, attempting to keep RPM between 2000 and 3500 RPM. During the test drive, monitor for the below conditions. If any of these conditions are found during the test drive, immediately return to the dealership, keeping the engine RPM as low as possible and avoiding heavy throttle.

• Normal Engine Operating Temperature
• No abnormal valve train noise
• No check engine light (especially P0300 or P030X)
• No abnormal burning smells (catalytic converter break-in smell is normal operation).

If both the high-idle test and the road test complete successfully without any of the above described issues, no further testing is required.

Perform an oil change. Refer to Engine Oil and Oil Filter Replacement in SI.

Dealer Responsibility

Dealers must take the steps necessary to ensure that the service update correction has been made to all involved vehicles in dealer inventory before selling or dealer-trading the vehicle, but no later than November 30, 2021.

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 andmust 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.

Article ID: 1472
Created: November 23, 2020
Last Updated: November 23, 2020
Author: Rob Loszewski

Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article.php?id=1472