2016 Buick Lacrosse

The 9T50 (Hydra-Matic 9T50) nine-speed automatic transmission exhibits harsh and erratic shifting, particularly during low-speed driving. Owners report clunking when shifting from Park to Drive or Reverse, delayed upshifts, and a noticeable lurch between 1st and 2nd gear. The transmission may also hunt between gears while cruising on slightly hilly terrain.

Dealer performs a TCM (Transmission Control Module) software reflash with the latest calibration, which GM has updated multiple times. If shifting issues persist, the valve body or internal solenoid pack may need replacement. Reference GM TSB 18-NA-284 for 9-speed transmission shift quality improvements. A complete transmission fluid exchange may also improve shift quality.

The StabiliTrak and traction control warning lights illuminate intermittently, sometimes accompanied by a 'Service StabiliTrak' message. When the warnings activate, the system may reduce engine power unexpectedly, even on dry pavement. The issue is often caused by a faulty steering angle sensor, wheel speed sensor, or a software glitch in the electronic stability control module.

Dealer diagnoses the specific fault code stored in the EBCM (Electronic Brake Control Module). Common fixes include replacing a faulty wheel speed sensor, cleaning or replacing the steering angle sensor, or reprogramming the EBCM. Reference GM TSB 15-NA-113 for StabiliTrak warning diagnosis. Ensure all four tires are the same size and properly inflated.

LaCrosse models equipped with the optional Continuously Variable Real-Time Damping (CVRTD) suspension develop leaking rear shock absorbers and, on models with rear air leveling, the air springs lose pressure overnight causing the rear to sag. Standard shock-equipped models also experience premature rear shock wear, resulting in a bouncy ride and poor handling.

Replace the rear shock absorbers with OEM or quality aftermarket units. For models with air leveling, replace the air springs and inspect the compressor and lines for leaks. Some owners convert from air suspension to conventional coil springs and shocks to eliminate future air system failures.

The Buick IntelliLink infotainment system with the 8-inch touchscreen freezes during use, exhibits significant input lag, and occasionally reboots while driving. Bluetooth audio drops out, navigation destinations take excessive time to calculate, and the system may fail to pair with phones after a software update. Some owners report the screen going completely black and requiring a vehicle restart to recover.

Dealer performs an infotainment system software update. A master reset of the infotainment system (through the settings menu) may resolve software corruption. If freezing persists after updates, the infotainment control module may need replacement. Ensure USB cable connections are secure, as a loose cable can cause CarPlay/Android Auto disconnections.

The 3.6L LGX V6 engine can consume oil between changes, with some owners reporting a quart consumed every 2,000-3,000 miles. The piston rings may not seat properly, allowing oil to pass into the combustion chamber. Symptoms include low oil level warnings between scheduled oil changes, blue tinge to the exhaust smoke, and fouled spark plugs.

Monitor oil level frequently and top off as needed. GM considers oil consumption of up to 1 quart per 2,000 miles within normal parameters for this engine. If consumption exceeds that threshold, an oil consumption test may be performed under warranty. Severe cases may require piston ring replacement, which involves removing the engine for disassembly.

General Motors LLC (GM) is recalling certain model year 2014-2016 Buick Lacrosse and Chevrolet Spark EV, Caprice PPV and SS vehicles, 2014-2017 Buick Encore and Chevrolet Corvette, Silverado 1500 and GMC Sierra 1500 vehicles, 2015-2016 Cadillac Escalade and Escalade ESV, Chevrolet Tahoe, Trax, Suburban and Silverado 2500 and 3500 and GMC Yukon and Yukon XL vehicles, and 2015-2017 GMC Sierra HD 2500 and 3500 vehicles. While being previously remedied for recall 16V-651, the affected vehicles may not have received the complete software update necessary to remedy the recall condition. Without the update, certain driving conditions may cause the air bag sensing and diagnostic module (SDM) software to activate a diagnostic test. During this test, deployment of the frontal air bags and the seat belt pretensioners would not occur in the event of a crash.

A failure of the front air bags or seat belt pretensioners to deploy in the event of a crash necessitating deployment increases the risk of injury to the driver and front passenger.

GM will notify owners, and dealers will reflash the SDM software. Vehicles that have had a previous air bag deployment will have the SDM replaced. These repairs will be performed free of charge. The recall began on August 4, 2017. Owners may contact Buick customer service at 1-800-521-7300, Cadillac customer service at 1-800-458-8006, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-800-462-8782. GM's number for this recall is 17287.

General Motors LLC (GM) is recalling certain model year 2015-2017 Chevrolet Silverado 2500 HD, 3500 HD, Tahoe, Suburban, GMC Sierra 2500 HD and 3500 HD, GMC Yukon, GMC Yukon XL, Cadillac Escalade and Cadillac Escalade ESV vehicles and 2014-2017 Chevrolet Corvette, Silverado 1500, Trax, Caprice Police Pursuit Vehicle, GMC Sierra 1500, Buick Encore, and 2014-2016 Buick Lacrosse, Chevrolet Spark EV and SS vehicles. In the affected vehicles, certain driving conditions may cause the air bag sensing and diagnostic module (SDM) software to activate a diagnostic test. During this test, deployment of the frontal air bags and the seat belt pretensioners would not occur in the event of a crash.

A failure of the front air bags or seat belt pretensioners to deploy in the event of a crash necessitating deployment increases the risk of injury to the driver and front passenger.

GM will notify owners, and dealers will reflash the SDM software. Vehicles that have had a previous air bag deployment will have the SDM replaced. These repairs will be performed free of charge. The recall began on October 13, 2016. Owners may contact Buick customer service at 1-800-521-7300, Cadillac customer service at 1-800-458-8006, Chevrolet customer service at 1-800-222-1020, or GMC customer service at 1-800-462-8782. GM's number for this recall is 16007.