GMC Sierra 4-Wheel Drive Problems: Common Issues and Solutions

The GMC Sierra is one of the most popular trucks in the US. It's generally considered one of the best full-size pickup trucks available on the market. With a reputation for safety and reliability, it's easy to see how this vehicle has achieved its popularity. However, like most vehicles, it has its particular issues and problems.

So, what are the common issues and problems with the GMC Sierra 4-Wheel Drive? You should expect to deal with minor issues like a bad fuel level sensor or blistering door handles. You may also face more serious problems like a failed transfer case position sensor, excessive oil consumption, or a clunking noise from the steering wheel.

These are just some of the common problems that you might face with your GMC Sierra. In this article, we'll discuss some more common issues that your vehicle might face, as well as how to fix them when they arise.

Common Issues with GMC Sierra

There are quite a few problems you can expect to run into with the GMC Sierra 4-Wheel Drive. Most of these issues are minor problems that can be fixed inexpensively, while some of them might require costly repairs. There is no reason to fear though. Being aware of these problems and taking the right precautions will prevent them from growing into major issues.

Here are the common issues affecting the GMC Sierra 4-Wheel Drive, as well as how to fix them.

1) Four-wheel-drive Transfer Case Position Sensor Failure

A huge issue with Sierra owners is a failure of either the transfer case position sensor or the selector switch. This error is displayed through a "Service 4WD" error message. When this failure occurs, you might find that you are unable to switch to four-wheel-drive when you need it. You may also notice the car shifting out of four-wheel-drive on its own.

How to Fix This Problem: If you see the "Service 4WD" message, you can use an OBD2 scan tool to search for error codes. These should help you diagnose the cause of the problem. If the issue ends up being the transfer case position sensor or the selector switch, then you will need to have the faulty part replaced.

2) Heating and Air Conditioning Malfunction

The most common problem with the Sierra is heating and air conditioning malfunctions. It is usually experienced as very hot or very cold air coming from the AC vents. This is due to a faulty blend door actuator.

A blend door actuator opens and closes the blend door, which is a flap that controls the flow of hot and cold air through the vents. By adjusting the positioning of the door, the climate control system can create the desired temperature in the car. When the actuator fails, the door is stuck in one position, resulting in airflow that is too hot or too cold.

How to Fix This Problem: The problem can be fixed by replacing the faulty blend door actuator. If you have experience in automotive repair, you can order the replacement and install it yourself. If you are not comfortable with opening part of the dashboard, it is an inexpensive repair that can be done by a mechanic.

3) Fuel Level Sensor Malfunction

Another common issue with the Sierra is a faulty fuel level sensor. This sensor is located inside the gas tank and reports the level of fuel inside the tank.

A sign of this problem is your fuel gauge showing the wrong amount of fuel. You might notice that the gauge hits empty and the car still runs like the tank is still half full. Or you suddenly run out of fuel despite the gauge claiming to be full.

How to Fix This Problem: Fixing this issue will require replacing the fuel sensor. Since the fuel sensor is inside the fuel tank as part of a module with the fuel pump, some mechanics recommend replacing the fuel pump at the same time.

4) Fuel Pump Failure

A common problem with the GMC Sierra is a failure to start. This is usually caused by a faulty fuel pump. When the pump is unable to move fuel from the tank to the engine, the car won't be able to start.

How to Fix This Problem: When the fuel pump fails, it will need to be replaced. This process will involve removing the fuel tank since the fuel pump is submerged in the tank. Since the fuel level sensor in the GMC is prone to malfunctioning, it is advisable to replace the entire fuel pump module at once.

5) Clunking Sound from the Steering Shaft

A common complaint with the Sierra is a clunking sound from the steering shaft. Any noise coming from under the hood is worrying, and this is no exception. While you might not notice any changes in steering, it is still best to address the problem as soon as possible.

How to Fix This Problem: This can be fixed by lubricating the bearings in the steering shaft. GMC released a lube kit that comes with the tools needed to make this job easier.

Some Sierra owners recommend replacing the steering shaft altogether to get rid of this problem completely.

6) Gauge Cluster Failure

The gauge cluster on the Sierra can become inaccurate, and give erratic readings. This results in all of the gauges, such as the fuel gauge, oil pressure gauge, and speedometer becoming unreliable. Naturally, this poses a safety hazard, as you won't be able to accurately monitor the vehicle's vitals.

How to Fix This Problem: A faulty gauge cluster will need to be replaced. Due to the prevalence of the issue, GMC offers a discount for gauge replacement, so you should have it replaced at a GMC dealership.

7) Broken Door Handles

The door handles on the GMC Sierra will sometimes break. This can happen on either the inside or the outside of the handle.

The door handles on the Sierra are covered with chrome plating that blisters and cracks under direct sunlight. The peeled layers of chrome plating are very sharp and can cut the driver's or passenger's hands.

How to Fix This Problem: Broken door handles will need to be replaced. This is a simple procedure that is inexpensive and can be done yourself if you have the right tools and experience.

You can protect the chrome on the door handles from flaking by covering them with clear metal epoxy. This will protect them from rain and water that could speed up corrosion.

8) Battery Drains Quickly

Batteries do not last very long in the Sierra. It has high power usage that causes the battery not to last as long as it would in another car.

How to Fix This Problem: The Sierra has an extra battery rack to mount another battery, which you should consider using, in case the battery runs out on a trip. You should also consider carrying jumper cables and a portable battery charger.

9) High Oil Consumption

A common problem with Sierra's from 2007 to 2013 is excessive oil consumption. This problem occurs because of the Active Fuel Management (AFM) system. This system shuts down the cylinders at low RPMs to decrease fuel usage. However, it also results in excessive oil consumption.

How to Fix This Problem: The problem is managed by performing frequent oil changes. It is also a good idea to carry some spare oil in the car, in case you suddenly find yourself low on oil. Another solution is having a professional deactivate the AFM with an engine tuner. It is possible to cause damage to the engine with this, so it should only be performed by a professional.

Which GMC Sierra Years Are the Least Reliable?

While the Sierra is a model that is plagued by certain issues, not all models of this car suffer too many issues. Knowing which model years to avoid can save you a lot of time and money spent on repairs and maintenance.

A good measure of reliability in a car is the frequency of problems developing at low mileage. This is especially important if you're buying a used car that already has quite a few miles on it.

The GMC Sierra model years with the most complaints are the 2004 and 2007 models. The 2002, 2003, 2005, and 2010 models also gather many complaints.

Many of the problems that affect these models tend to appear at low mileage. Because of this, it's advised that you don't buy these models used.

Conclusion

The GMC Sierra is a safe and reliable vehicle, with performance that makes it one of the most popular trucks on the market. Despite this dependability, there are some issues that are common with this model. Knowing what these issues are will help you know what to look out for if you own this vehicle.

The most common issues in the Sierra are the transfer case position sensor failing, air conditioning malfunctions, and a faulty fuel level sensor. Other issues include the battery draining quickly, bad door handles, and excessive oil consumption.

If you're planning to buy a used GMC Sierra, you should make sure to avoid the model years 2002-2005, 2007, and 2010. These are the least reliable models of this vehicle.