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2014 XTS 4 CPO
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Discussion Starter #1
I got in my 2014 xts a while ago and started up town. About 1/2 mile down the road I went over a small bump and my car started bouncing like it had no rear shocks. I turned around and returned home and it scraped the rear coming into my driveway.
I called the dealer where I bought it and they said the air ride must have a pin hole in something causing it to leak. I think it must be something not letting it work, but they said no a pin hole will make it do that.
Anyone had this before or know what it could be.

The will repair it next week but i'll have to get it to them. It is CPO covered I think.
 

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2013 XTS4 Platinum '91 Caprice Wagon '15 Impala LTZ (wife's)
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434 Posts
The air springs make for a great ride and the self leveling is very nice, but they do need to be air tight. The circumstances sound like the dealer is right. Can you hear the pump running continuously? I think about this when I'm on a trip. How many miles and are you in a harsh climate?
 

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2014 XTS 4 CPO
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107 Posts
Discussion Starter #3
I don't think I hear the compressed running, I'll go see if I can hear it.
 

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2014 XTS 4 CPO
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107 Posts
Discussion Starter #4
Ok just went out and started car. Raised hood to see if I could hear compressor. Then went to rear wheel area and heard it running. Car lifted back up like normal. What give? Can I trust it to drive 75 miles to my dealer?
 

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2016 Escalade ESV, 2017 GMC Sierra 6.2
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1,235 Posts
Theses cars never “pinhole” leak. By far the most common issue is the compressor failing.
 

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2014 XTS 4 CPO
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107 Posts
Discussion Starter #6
Could it have been the control system needed to re set. If so is this going to happen all the time or just one and done, hopefully.
 

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2014 XTS 4 CPO
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107 Posts
Discussion Starter #7
Well after coming back up yesterday and staying up all night I drove to town this morning. Everything was good until I got back in the car to head home. As I was pulling out I noticed I did not hear the compresser and sure enough the rear end sat back down. Not able to get I it back up yet. Plan to take to dealer tomorrow. Darn thing just will not behave, acts up every time I take it to town.
 

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2014 XTS 4 CPO
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107 Posts
Discussion Starter #8
Ok more info: the compresser runs for a while on start up, but the car doesn't lift.
 

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'02 ETC CE, '04 CTS-V, '04 XLR, '13 XTS Platinum
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2,521 Posts
Could be a weak compressor, bad vent valve, leak in an air line, or faulty level indication sensor. Your dealer should be able to repair it pretty fast as long as parts are available. It should also be covered under the CPO warranty. I had the same symptoms as you and the problem was traced to both suspension sensors failing.

Here's how the system works:

Air Suspension Compressor Assembly

The Air Suspension Compressor Assembly houses the DC motor/air compressor, an Exhaust Valve Solenoid, and two Air Spring Isolation Valve Solenoids. The ESCM sends a voltage signal to each height sensor and measures the inductance of the return signal to determine if one or both air springs need to be inflated or deflated. Before the compressor starts, the exhaust valve is activated, providing compressor head pressure relief. Next, the Compressor Relay activates to start the compressor. When the trim height is achieved the relay is de-energized. To prevent the compressor from overheating, the compressor operates on a duty cycle. If the compressor is requested to operate continually, the compressor duty cycle is limited to 300 seconds at maximum output for the first cycle. After this time, the compressor automatically switches off for at least 92 seconds. After that, the compressor activates for 16 seconds and de-activates for 92 seconds. This 16/92 second duty cycle continues until the compressor can remain off for more than 92 seconds.

The Air Suspension Compressor Assembly has three different operating modes:

• Single Value Mode inflates and deflates the two air springs independently. This is the normal operating mode of the system. The system will enter Mean Value Mode when the sensor output indicates the difference between the height on each side is greater than 15.5 mm.

• In Mean Value Mode, the ESCM averages the signals from each height sensor to maintain an average trim height. If the measurement differential between the two (side) heights reaches approximately four mm, the system will enter Lock Mode and no leveling occurs. This compensates for uneven loading of the vehicle or if the vehicle is parked on an uneven surface. The Air Suspension Compressor Assembly has a wheel change (jack) control that prevents the air springs from deflating completely. If the ESCM detects that one or both of the rear wheels has a side height measurement of more than 235 mm, the system enters Lock Mode and suspends leveling functions until the suspension is moved toward the frame.
In some cases, the Air Suspension Compressor Assembly may set a flag that requires resetting the ESCM. The ESCM will reset on its own after the ignition has been turned off for more than 2 1/2 hours or if the air suspension fuse has been removed with the ignition turned OFF.


You may get an error message on your DIC:


Automatic Level Control

The Automatic Level Control (ALC) system maintains a desired rear suspension position under all types of loading conditions.

When the vehicle is unloaded, the rear suspension is at a desired position, which is monitored by the ESCM using the position sensor signal voltage inputs. As weight is added to the rear of the vehicle, the position sensor's signal voltage inputs change. When the ESCM detects a steady substantial change in the position sensor signal voltages for at least 10 seconds, it responds by commanding the compressor relay ON, which activates the compressor causing the air pressure in the air spring to inflate. This inflation raises the rear of the vehicle to regain the desired suspension position. When weight is removed from the vehicle, the ESCM responds by commanding the exhaust valve ON causing the air pressure in the air spring to deflate. This deflation lowers the vehicle to regain the desired suspension position.

The compressor is a positive displacement piston air pump driven by a 12-volt DC permanent magnet motor. The compressor draws filtered air through an intake line attached to an under body rail. The compressed air is sent through a dryer containing a moisture-absorbing chemical that dries the compressed air before it is sent to the air springs. Each time the compressor activates, the ESCM commands the exhaust valve ON for 1.5 seconds to release air from the compression chamber in the compressor’s cylinder head ensuring low motor current draw upon compressor activation. The ESCM also limits the amount of compressor run time to 180 seconds to protect the compressor components from thermal damage.

The ESCM has the ability to detect malfunctions within the ALC system. Any malfunctions detected will cause the DIC to display the SERVICE LEVELING SYSTEM message.
 

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2014 XTS 4 CPO
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107 Posts
Discussion Starter #10
Thanks CC, I'm thinking I have a valve sticking. I just hope my dealer understands the system as well as you do. My friend has a rollback to haul it to the dealer, he is worried it will drag going on or off the rollback.
 

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2014 Cadillac XTS Platinum Edition rear air suspension malfunctioning. Rear of car drops so low that the frame of the car is sitting on the rear wheels and the car can’t safely be driven. While I was waiting for a tow truck, I started the car and the rear end lifted up surprisingly. I was able to drive for five minutes and then the rear end bottomed out again and I couldn’t drive the car. Towed car home, Came out next day & started the car and the rear end corrected itself and once again I’m baffled & afraid to drive the car on any lengthy trip because I don’t want to get stranded and need a tow truck again. There is no error message showing on the dash either so I’m worried the dealer won’t be able to diagnose the problem unless the rear suspension malfunctions while at the dealership. Anyone have any suggestions on how to remedy this problem?
 

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'02 ETC CE, '04 CTS-V, '04 XLR, '13 XTS Platinum
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Obviously, from the repetitive symptoms you've given, your car isn't going to heal itself.

I'm no psychic, but unless you have the know-how and tools to diagnose and correct the problem yourself, I see a dealership trip in your future. . . .
 

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2014 XTS V Platinum
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42 Posts
When my air compressor failed I ended up getting both shocks replaced...….not really related (maybe) but they were leaking so said the mechanic.
 

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2016 Escalade ESV, 2017 GMC Sierra 6.2
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Rear shock leak is common on the XTS and is not related to the Air suspension operation. But they are in the same general area and that probably why the mechanic spotted the leaks.
 

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2014 XTS 4 CPO
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107 Posts
Discussion Starter #17 (Edited)
OK Picked car up today, they changed the compressor said it was compressor relay failure and internal compressor failure. Everything seems to be working good. Just think it is a bad setup that you cannot lock it in up position to drive it to repair shop.

Edit look to say lock.
 
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