New GM TechLink Article Highlights an Issue over the DCT Transmission in C8 Corvette E-Rays

By
Keith Cornett
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4
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New GM TechLink Article Highlights an Issue over the DCT Transmission in C8 Corvette E-Rays


General Motors has a new TechLink article available for service reps who may be chasing down some issues that pertain specifically to the C8 Corvette E-Ray’s dual-clutch transmission.

The GM TechLink article shows the error codes received and the process to alleviate the “DCT Transmission Auxiliary Pump Cavitation” as it’s referred to in the article.

The likely reason that this only affects the E-Ray is due to the hybrid system which allows the car to move under electric power only. To do so, the E-Ray (and the upcoming ZR1X) DCTs feature an auxiliary pump to circulate fluid when the while running in Shuttle or Stealth Mode.

If your error codes contain P1955 and/or P0867, this TechLink article is for you!

DCT Transmission Auxiliary Pump Cavitation
Posted October 30, 2025

Some 2024-2026 Corvette E-Ray models may have a Service Transmission message displayed on the Driver Information Center along with an illuminated Check Engine MIL. DTCs P1955 (Transmission Fluid Pressure Relief Valve Performance) and P0867 (Transmission Fluid Pressure Performance) may be set in the Transmission Control Module (TCM).

These conditions may be caused by auxiliary pump cavitation due to the transmission pan fluid filter.

If DTCs P1955 and/or P0867 are set as current or history DTCs, replace the transmission pan fluid filter and reevaluate the vehicle. Refer to Automatic Transmission Fluid, Fluid Pan and/or Filter Replacement in the appropriate Service Information. (Fig. 1)

DCT Transmission Auxiliary Pump Cavitation


Do not attempt any other repairs for these DTCs other than transmission fluid pan filter replacement.

TIP: When removing the transmission fluid pan, the 15 bolts are single-use fasteners. (Fig. 2) During installation, tighten the bolts in sequence according to the Service Information using the GM-45059-A Angle Meter.

DCT Transmission Auxiliary Pump Cavitation


For more information, including part numbers, refer to Bulletin #25-NA-278.

– Thanks to Marty Leach


Source:
GM Techlink via MidEngineCorvetteForum.com

Related:
GM is Making C8 Corvette Transmission Repairs Possible with New Parts Available
GM Issues TechLink Article for C8 Convertible Top Water Leaks
GM Offers Updated TechLink Article on Servicing the Transmission in the C8 Corvette

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4 COMMENTS

  2. GM quality is bad for $100,000+ cars. FBI is actually investigating GM for fraud but Mary will get her big bonus.

  3. That doesn’t sound like a fix, rather just swapping existing parts and seeing if the light goes off.

    If this is the kind of stuff that GM is keeping under wraps about the ER, it’s no wonder they’re incredibly slow to come out of the factory.

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