2020 - 2021 Corvette: GM TechLink: Multiple Transmission DTCs Set

March 1, 2021
GM TechLink

Some 2020 - 2021 Corvette models may have multiple DTCs set in the Transmission Control Module (TCM). The DTCs may be caused by an internal transmission solenoid or switch sticking due to debris in the DCT TR-9080 transmission (RPO M1L). (Fig. 20) Based on the DTCs that are set, GDS2 should be used to perform the appropriate solenoid cleaning procedure.

2020 - 2021 Corvette: GM TechLink: Multiple Transmission DTCs Set

Fig. 20

The cleaning procedure should be performed three times. If required, perform the solenoid cleaning for each additional DTC that may have set and complete the solenoid cleaning three times. Once completed, it will be necessary to perform the Service Clean Procedure followed by the Transmission Service Fast Learn.

TIP: The cleaning procedure is targeted for mechanical and hydraulic conditions. If circuit diagnostics are required to determine the repair, valve/solenoid cleaning, Service Clean, and the Service Fast Learn will not address the issue.

Cleaning Procedures Based on DTCs Set

Use GDS2 to perform the following cleaning procedures for the DTCs set in the TCM.

If DTCs P194F, P1950, P0747, P0746, P0777, P0776, P2809, P2808, P2724, P2723, P1955, P0797, P0796, P2715, P2714, P2818, P2817, P08C5, P08C4, P27BA, P27B9, P27C2, P27C1, P27CA, P27C9, P27D2, P27D1, P282A, P2829, P1956, P1957, P1958, P1959, and/or P2735 are set:

If DTCs P18A8, P18A9, P2821, P2820, P187D and/or P187E are set:

If DTCs P2855, P2853, P2856, P2854, P0869, P0868, P0867, C2A18 and/or C2A19 are set:

If DTCs: P0844, P0841, P0849, P0846, P0874, P0871, P0879 and/or P0876 are set:

If DTCs: P1946, P1947, P1948, P1949, P194A, P194B, P194C, P194D, P194E, P073F, P074A, P074B, P074C, P074D, P074E, P074F, P07D8 and/or P073E are set:

Perform the DTC solenoid cleaning procedure three times for each DTC set. Once the cleaning procedure has been completed three times, select the Configurations/Reset Functions in order to perform the Transmission Service Fast Learn procedure as needed.

Be sure to test drive the vehicle after performing the cleaning procedures to verify that the DTCs do not reset. If the DTCs reset, replace the Control Valve Solenoid (or Main Control Valve, MCV).

For additional information, refer to Bulletin #21-NA- 033.


– Thanks to Dave Rainey

Article ID: 1492
Created: March 1, 2021
Last Updated: March 1, 2021
Author: Rob Loszewski

Online URL: https://www.corvetteactioncenter.com/tech/knowledgebase/article.php?id=1492