A quick look at the exhaust pipe crossover section on 2019-2020 Silverado and Sierra models equipped with a V6 or V8 engine shows that it is not a completely round […]

The cooling system of the 6.2L V8 engine (RPO LT2) on the 2020 Corvette (Fig. 1) is designed to help maintain engine performance under extreme track environments. When filling the […]

Several DTCs may set after replacing the CVT7 transmission (RPO M4M) in some 2014-2015 Spark models. (Fig. 8) The most common codes that may set are P0797 (Pressure Control Solenoid […]

A belt chirp sound or metal-to-metal sound may be heard on some 2019-2020 Silverado HD, Sierra, HD and Silverado 4500HD/5500HD/6500HD models equipped with the 6.6L Duramax diesel engine (RPO L5P, […]

There may be a Service Front Leveling System message displayed on the Driver Information Center on some 2020 Corvette models. DTC U3000 SYM49 (Control Module Internal Malfunction) also may be […]

When diagnosing engine oil leaks on 2019-2020 Silverado, Sierra; and 2020 CT4-V models equipped with the 2.7L turbocharged 4-cylinder engine (RPO L3B) (Fig. 16), inspect the dipstick tube O-ring and […]

Some 2019-2020 Silverado and Sierra models may have any of several electrical-related concerns, including no crank, starter engages after engine start, flickering headlamps, erratic instrument cluster gauges, or high or […]

The enhanced exhaust brake is one of several improvements in 2020 Silverado and Sierra models equipped with the 6.6L Duramax diesel engine (RPO L5P). The exhaust brake feature can be […]

Some 2020 Encore GX and 2021 Trailblazer models may have several electrical conditions, including no audio from the radio, an inoperative power liftgate (RPO TC2), if equipped, and/or an inoperative […]

The monthly GM Service Know-How Emerging Issues seminars provide service/technical information on current issues and GM certified repairs. The latest service topics from GM Brand Quality and Engineering covered in […]

A new replacement program for the 9T65 9-speed automatic transmission (RPO M3V, M3W) (Fig.1) on 2018-2020 Enclave, Traverse; 2019-2020 Blazer; 2020 Acadia, XT5, and XT6 models is being piloted in […]

Inspection/Maintenance Test DTCs, commonly referred to as Permanent DTCs, are codes that are currently commanding on the Check Engine MIL (Malfunction Indicator Lamp) and are stored in non-volatile memory of […]

Techline Connect, GM’s integrated Service Technician Diagnostic Scan Tool application, provides dealership service and parts personnel with access to GDS 2, Service Programming (SPS) and Service Information (SI) from a […]

Corvette models have required the J-43625 Lift Pad Adapters to properly lift the vehicle since the C5 generation debuted in 1997. The lift pad adapters help ensure proper vehicle weight […]

After replacing the Diesel Exhaust Fluid (DEF) pump (Fig. 9) on some 2017-2020 Colorado, Cruze, Express, Silverado 1500, Silverado 2500/3500, Canyon, Sierra 1500, Sierra 2500/3500; 2017-2019 Savana; 2018-2019 Equinox, Terrain; […]

Some 2020 Encore GX and 2021 Trailblazer models equipped with the 1.2L engine (RPO LIH) may have an illuminated Check Engine MIL and DTCs P0521 (Engine Oil Pressure Sensor Performance) […]

A rattle or creak sound may be heard coming from the quarter panel area while driving at highway speeds on some 2020 Corvette models. The sound may be due to […]

2020 Corvette Stingray models equipped with the Z51 Performance Package feature a rear spoiler that adds downforce to improve high-speed stability. (Fig. 15) If the Z51 spoiler is to be […]

A customer may request the pickup box and rear bumper be removed on 2019-2020 Silverado 1500 and Sierra 1500 models to install an aftermarket bed or body. (Fig. 18) If […]

Proactive Alerts, a feature of OnStar Advanced Diagnostics, are designed to help predict specific types of potential performance degradation of the battery, cables, and starter motor based on current vehicle […]