Why isn’t My 2011 Jeep Grand Cherokee’s Air Suspension Working Properly?

Q: I have a 2011 Jeep Grand Cherokee. Over the last three years, I have spent a lot of time and money trying to fix the air suspension system. The dealer has replaced a 40 amp fuse, the compressor, the valve block, and two other valves they claim were leaking. The system still doesn’t work as it should. What could be the problem?

– Bruce

A: Hello, Bruce. Your Jeep’s air suspension system is quite complex. As I’m sure you know, the setup uses air springs in the front and rear to raise and lower the vehicle’s ride height. A computer, referred to as the Air Suspension Control Module (ASCM), manages the system based on inputs it receives from sensors (including height sensors) and other modules. The ASCM operates the compressor and valve block assembly to move air back and forth between the air reservoir and air springs.

When the ASCM detects a problem with the air suspension system, the module turns on a dashboard warning light and stores a corresponding diagnostic trouble code (DTC) in its memory. The code(s), which I’m assuming the dealer has retrieved, serve as a starting point for further troubleshooting.

Without knowing the codes, it’s tough to provide much insight as to what might be wrong with your Jeep. Also, you didn’t mention what problem the system is having, but I’m assuming the suspension either won’t raise properly or lowers after sitting for a while.

One thing I noticed is that the air springs aren’t on the list of parts that have been replaced. It’s very common for the springs to develop small leaks and starve the system of air. When that happens, the compressor has to work extra hard and often burns out as a result. If the dealer hasn’t done so already, it might be a good idea to check the lines and air springs for leaks using soapy water.

It’s also important to point out that, after any repairs have been performed, the system needs to be manually refilled (the compressor is not designed to refill the system on its own) using the factory scan tool and a nitrogen tank. Failing to do so will prevent the system from working properly.

Finally, perhaps the best piece of advice is to take your Jeep to another dealership if possible. You might have better results at a different location. 

Good luck!