More than 253,000 GMC Sierra trucks were sold in the United States in 2020. They are the fifth most common pickup in the country. Chevrolet Silverado and GMC Sierra were launched by General Motors around the same time in 1998. Since 1999, four generations have been released: 1998-2007, 2007-2014, 2014-2019, and 2019-current.

GMC Sierras and Chevy Silverados have identical engines, chassis, and general technologies. The Sierra models have a slight advantage in terms of interior finishes, but mechanically they are the same. While the GMC Sierra has been so popular, its early-year models have shown faults similar to those found in Silverados, such as HVAC control failure and transmission problems. is just one of many websites on which consumers report problems they have had with their vehicles. RepairPal has collected reports from thousands of GMC Sierra owners about more than 112 different problems. Most complaints have come from drivers who owned trucks manufactured in the 2004 and 2007 model years. Other years’ models that appear frequently in complaints include 2002, 2003, 2005, and 2010. Few complaints appear for the later model years primarily because many of the trucks are still under warranty. The problems, however, are still lurking under the hood.

Michael J. Goodman Lemon Law PLLC stands ready to assist you if you own a GMC Sierra with problems. Michael J. Goodman has exceptional experience in protecting the rights of Arizona drivers with defective vehicles.
Here are some of the significant issues that GMC Sierra has experienced during its nearly 25-year history. If you haven’t encountered one of these defects yet, you probably will.

Defective 4WD Switch and Sensor

The most prevalent problem on GMC Sierras is failure of the selector switch or the position sensor of the transfer case. When this switch or sensor quits working, the “service four-wheel-drive” message appears on the dashboard. The specific fault codes are stored in the controller of the transfer case. These codes enable a service technician to determine the exact cause of the breakdown. Failing switches and sensors persist in vehicles manufactured between 1999 and 2013 as well as in 2015 and 2016. The problem typically begins for many consumers at around 147,000 miles. Diagnosing this problem costs from $88 to $111. The sensors themselves run between $20 and $80, plus the labor to install them.

Faulty HVAC Actuator

The truck’s heater and air conditioner, along with the air delivery mode door actuators, are also among the biggest problems in GMC Sierra vehicles. You know you have a problem when the heating and air conditioning unit will not produce the correct air temperature when one of the delivery mode door actuators stops working and is stuck in either the open or closed position. The HVAC system stores fault codes that later help mechanics detect the problem. This particular defect occurs among the Sierras from model year 1999 to 2015. The actuators go bad when the vehicle reaches an average of 126,000 miles. Diagnosis runs $88 and $111, and the repair costs between $100 and $400.

How to tell if your HVAC Actuator is Failing

  • Throwing cold air when it needs to blow hot and vice versa.
  • Irregular air speed.
  • AC ignores the temperature settings and only throws either cold or hot.
  • The dashboard makes ticking noises when the air runs or the car is turned on.

Fault in the Fuel Level Sensor

Bad fuel level sensors are the third most commonly reported defect in GMC Sierra trucks. With this defect, the vehicle’s fuel tank fails to read the fuel level accurately. This issue can be fixed either by replacing the fuel sensor or by changing the fuel pump control module. There were many reports of this problem from the model years 1999 to 2014. Problems seemed to appear at 127,000 miles on average. It typically costs from $687 to $926 to replace the fuel pump. Luckily, fuel level sensors aren’t that expensive—you can get them for $25, plus labor.

Symptoms of Fuel Level Sensor Failure

  • Inconsistent reading of the gas gauge.
  • The gas gauge shows a greater loss of fuel than normal.
  • The gauge displays “full tank” even when the tank isn’t full and “empty tank” after it is refilled.

Excessive Oil Consumption

Many GMC Sierra owners have reported an excessive oil consumption issue with their 2007 to 2013 models. Consumers took action against General Motors over this issue by filing a class-action lawsuit. The lawsuit stated that GMC Sierras between 2010 and 2013 equipped with the 5.3L Vortec engine are flawed. Essentially, the lawsuit alleged that there is a problem with the vehicles’ PVC system, piston rings, and Active Fuel Management (AFM) system. Consequently, the trucks are experiencing premature spark plug degradation, malfunctioning of engine, and high oil consumption.

Usually, the problem arises because of the AFM system, which causes the cylinders of the engine to shut down at low RPMs in an effort to decrease fuel usage. Although the system’s mission is likely to be achieved, at the same time, it also causes a huge oil usage problem. People who experienced high oil consumption reported driving for a thousand miles and found the engine oil to be a quart low. The problem begins to appear when the truck reaches around 60,000 miles.

The problem can be resolved by changing the truck’s oil frequently. Additionally, drivers should think about having a spare quart of oil in their vehicles all the time. Some owners have come up with the solution of deactivating the AFM system by using an engine tuner. This method can be quite effective, so long as the tuning is performed correctly so as not to damage the truck.

Battery Dies Frequently

The battery problem in GMC Sierras most commonly starts to appear at around 30,000 miles. Car batteries typically last much longer than 30,000 miles. If you are considering buying Sierra, expect to spend $200 to $250 more per 30,000 miles for a battery. If you frequently drive your Sierra on long trips, you might consider carrying a portable charger and jumper cables in your truck.

Although GMC Sierra trucks have an extra battery tray that can be used to attach an extra battery, it will not stop the battery from running down. The real cause of the excessive battery drain is unknown, but a malfunctioning anti-lock braking system pump could be the reason.

Problems with Speakers

Bad speakers are another issue that most Sierra drivers encounter. Owners often complain of malfunctioning speakers, particularly those mounted in the door. Several months after the vehicle is purchased, the speakers stop working one by one. They may appear to start working again and then stop after a while. The moisture in the truck’s doors might be the cause of this problem.

The broken speakers primarily result in the loss of entertainment while driving, which is a nuisance, but not life-threatening. The lack of speakers, however, can also impact safety since OnStar doesn’t work if all speakers are dead.

The issue can be resolved easily by replacing the speakers within your vehicle. If you want a quick fix, you can go to a discount store and purchase cheap ones. Poor quality speakers, however, may cause the problem to appear again after a while. It is better, therefore, to spend the time and money on good quality speakers that will last longer.

Fault in Speedometer and Other Gauges

Many drivers complain about issues with various gauges in their instrument panels, mainly the speedometer. The problem can be fixed only if the instrument cluster is serviced by an authorized repair shop. To counter the many complaints about gauge failures, General Motors extended the warranty life of the truck several years ago to 70,000 miles.

The problem seems to pop up more in the GMC Sierra’s early models, such as 1999-2005. Newer models, however, including 2007, 2011, 2012, and 2016, have also encountered the issue. The fault within the vehicle’s speedometer occurs when the truck reaches an average of 107,000 miles. The cost to diagnose the gauge problems in the instrument panels is typically between $88 and $111. The cost of the actual fix depends on the nature of the problem.

What to Do If You Just Bought a GMC Sierra Lemon

In the event you recently purchased a new or used GMC Sierra in Arizona and are experiencing persistent problems with it, if the truck is still under warranty, the manufacturer or dealership has the duty to rectify the fault. If, however, after numerous repair attempts, your truck is still not up to par, then you might have a lemon on your hands and have a right to file a claim.

If you don’t know whether your GMC Sierra qualifies for a claim or not, feel free to contact Michael J. Goodman Lemon Law PLLC for a free consultation. Michael J. Goodman has offices in most major metropolitan locations in Arizona and a staff of experienced attorneys to handle your lemon case. Michael is Arizona’s premier Lemon Law attorney. He treats every case with professionalism and evaluates each client’s case accurately.