Learn the top 5 GMC Sierra 3500 problems like defective knock sensors and the AC not working. This post reviews the most common problems and how to fix them.
Top 5 Issues with the GMC Sierra 3500
1. Knock Sensor Failure
Symptoms of Knock Sensor Failure
- Check engine light for a knock sensor code
Causes of Knock Sensor Failure
If there is a code related to a knock sensor on the Sierra 3500, chances are the knock sensor needs to be replaced.
How to Fix Knock Sensor Failure
The knock sensors are sensitive so it’s important to torque them to the proper specifications. The wiring harness may also need to be replaced if the wires are damaged.
The knock sensor on older models is underneath the intake, so confirm the replacement knock sensor is for a location on the side of the engine.
2. AC Belt Tensioner Failure
Symptoms of AC Belt Tensioner Failure
- AC is not working
Causes of AC Belt Tensioner Failure
The AC belt tensioner puts tension on the AC compressor belt. If the AC is not working on the 2007 to 2014 Sierra 3500, it’s likely the compressor belt is worn or fell off.
How to Fix AC Belt Tensioner Failure
If the AC is not working on the Sierra, see if the AC compressor belt fell off. If the belt fell off, replace the AC compressor belt and the AC belt tensioner. This repair also requires removing the serpentine belt.
3. Electrical Problems—Bad Grounds
Symptoms of Electrical Problems on the 2007 to 2014 GMC Sierra 3500
- Electrical issues like door locks cycling on their own or the dash lights flickering
Causes of Electrical Problems
There is a ground on the passenger side of the engine that connects to the negative battery terminal and the engine wiring harness. Sometimes this ground or the wire corrodes and causes electrical problems.
How to Fix Electrical Problems
Loosen the stud nut and clean the engine ground.
If there is green corrosion on the electrical cable, replace it.
If any ground straps are broken, replace them.
Inspect the ground underneath the driver side door. Clean the bolt and retighten it.
4. Front Impact Sensors
Symptoms of Front Impact Sensors
- Air bag light is on and reads for a front impact sensor codes
How to Fix Front Impact Sensors
Disconnect the battery. Pull the lock on the electrical connector and disconnect it. Remove the bolt from the sensor and remove the sensor. Replace the bolt, torque it, reconnect the sensor, and then reconnect the battery.
5. Inner Tie Rod End Failure
Symptoms of Inner Tie Rod End Failure
- Loose steering
Causes of Inner Tie Rod End Failure
Sometimes play in the inner tie rod end causes loose steering.
How to Fix Inner Tie Rod End Failure
Raise the vehicle and shake the tire back and forth. See if the tie rod end is moving in and out, which means it needs to be replaced. Loosen the jamb nut on the tie rod and remove the tie rod by removing the tire and the castle nut and rotating the tie rod end off or by just loosening it with pliers, which can be a little more time consuming, and an adjustable wrench.
3rd Generation GMC Sierra Model Years
- 2007 GMC Sierra 3500
- 2008 GMC Sierra 3500
- 2009 GMC Sierra 3500
- 2010 GMC Sierra 3500
- 2011 GMC Sierra 3500
- 2012 GMC Sierra 3500
- 2013 GMC Sierra 3500
- 2014 GMC Sierra 3500
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