Gmc: Sierra 1500 Sle on 2040-cars

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GM opens official investigation into C8 Corvette transmission leaks

In March 2020, a month after Chevrolet began customer deliveries of the 2020 C8 Corvette, a GM dealer technician created a Reddit thread about a leaking gearbox in a Corvette with 32 miles. That car hadn't even been sold yet. Since then, as a search of "C8 Corvette transmission leak" shows, it's been tales of woe for some owners. Something in the Tremec TR-9080 transaxle in the back of the mid-engined Corvette doesn't work as it should, the fault able to cause codes that the transmission needs service, or that the driver needs to shift to park. In some cases, the battery would die because of follow-on issues after the initial transmission code, that code preventing the car from powering down. As Autoevolution reports, GM filed paperwork with the National Highway Traffic Safety Administration in August to look into what's going on. Between forum threads and GM's investigation document, there are several issues mentioned. The most common appears to be the dual-clutch transmission leaking fluid due to gasket failures like the one suffered by one owner at 858 miles, and another for an owner currently enduring a second leaking transmission. The Midengined Corvette Forum reported that Chevy engineers redesigned the TR-9080 pan, fitting Corvettes with the new unit at some point in the 2021 model year. The original pan was stamped steel unit affixed to the engine with two studs and 13 bolts, plus "reinforcement plates." The updated pan is said to be a cast aluminum unit affixed with two studs and 17 bolts, omits the reinforcement plates, and gets a new machined new groove around its edge to seat the gasket seal. The GM paperwork now at the NHTSA mentions a P1789 code, and says one reason for it could be "debris on the park position sensor magnet causing an incorrect position reading to the TCM." This might be caused by another issue mentioned in forums, which is clogged transmission filters. GM gives instructions for returning transmission filters to the company, and a poster on one forum said the Corvette tech at the dealer where he bought his Corvette told him the automaker "requires every used transmission filter to be returned to GM."  Whatever's going on, the problems haven't stopped, and they go beyond the P1789 code. Over the weekend, a 2022 Corvette owner posted on Corvette Forums that he got a check engine light on his car after just 850 miles.

GMC Syclone spools up a storm on Jay Leno's Garage

A storm was brewing on American roads in the early 1990s. That's when Detroit's automakers were producing some of the hottest performance trucks ever devised – models like the Ford Lightning, GMC Typhoon, and its flyweight pickup sibling, the GMC Syclone. Jay Leno just happens to have one of the latter in his garage, and took it out to showcase in this latest video segment. The Syclone was an exercise in absurdity, and could not only trounce any other pickup on the road, it could outrun anything else GM made and just about anything else on the road – beating Ferraris and Porsches off the line. In a pickup, for crying out loud. The kicker is that its engine wasn't such a monster, either: under the hood sat a 4.3-liter turbocharged V6 pumping out what would seem by today's standards to be an adequate 280 horsepower and 350 pound-feet of torque. Even the smaller of the EcoBoost V6s available in today's Ford F-150 produces more than that. But in a lightweight, compact pickup, those figures were enough to propel the Syclone to 60 in 4.3 seconds and run the quarter-mile in 13.6 seconds. Long before the dune-jumping Ford F-150 SVT Raptor or even the Viper-powered Dodge Ram SRT-10, GM made fewer than 3,000 Syclones based on the compact Sonoma (sister to the Chevy S-10) and another 4,700 of the Typhoon, which was mechanically similar but more practical (albeit heavier) wagon bodywork from the Jimmy. But as Jay aptly points out, the Syclone was the one you wanted. Scope it out in the ten-minute video clip above.

GM recalls 740,000 vehicles over daytime running light issue

General Motors is recalling over 740,000 vehicles due to a daytime running light issue that causes all of the affected cars to run afoul of Federal Motor Vehicle Safety Standards. Vehicles affected by this recall are spread across many of GM’s brands. Models include the 2020-2023 Cadillac CT4 and CT5, 2021-2023 Buick Envision, 2022-2023 Cadillac Escalade and Escalade ESV, 2022-2023 Chevrolet Silverado 1500, Suburban, Tahoe and 2022-2023 GMC Sierra 1500, Yukon, and Yukon XL. GM says that the daytime running lights may remain on in these cars when the headlights are activated. This is a problem, because FMVSS rules require that the daytime running lights deactivate once the headlights turn on. If the DRLs remain on, GM says that could result in additional glare, thereby increasing the risk of an accident. The cause of this failure to deactivate the DRLs comes from body control module software that “under a combination of certain pre-conditions, could fail to deactivate the DRLs,” according to GM. Other GM vehicles were tested, but due to a difference in software or hardware, they remain unaffected. If this is reminding you of another recent GM recall, youÂ’d be right, as GM recalled another 340,000 vehicles for the same issue last month. After that original issue was found within GM, the company began looking into its other cars to determine if the population was larger than originally thought. GM found the additional vehicles included in todayÂ’s recall have the problem. The fix will either be via an over-the-air update or it will require you to bring the vehicle into a dealer for a software update, depending on which vehicle you have. Owner notification letters letting folks know what is necessary are currently scheduled to go out on January 23, 2023. Related video: Cadillac Escalade Infotainment Review