In this brief article we are going to discuss the different GMC Envoy Air Suspension problems, what the causes are, and Troubleshooting Tips.
Most common Air suspension issues in the GMC Envoy?
The most common air suspension issues seen in the GMC Envoy are:
- Clunking Noise in the Front End
- Front Shock Absorber Strut Failure
- Rear Shock Absorber Failure
- Front Control Arm Failure
- Front Wheel Bearing Failure
- Rear Trailing Arm Failure
What suspension does the GMC Envoy have?
The GMC Envoy was first launched as a Mid-size SUV produced from 1998 to 2009 model years. The Envoy was basically the rebranded version of the Chevrolet TrailBlazer, Oldsmobile Bravada, Buick Rainier, Isuzu Ascender, and Saab 9-7X.
The GMC Envoy has a 5-Link live-axle rear suspension with a Coil Spring or a load-leveling air suspension, Shock absorber and an anti-roll bar.
Air Strut failure
- Rear suspension sits low
- Hissing noise from the rear of the vehicle
Troubleshooting Air Strut Failure
- Once the engine starts, the compressor automatically comes on as well and tries to maintain the air pressure that is required for the suspension to function.
- The Hissing noise is basically from a leakage point within the Air circuit. The fact that it is continuous, also gives a clue that it is indeed from the air suspension system.
- The air suspension system tries to maintain pressure all the time. The leakage creates a drop in pressure, which the compressor tries to overcome by overworking.
- The leakage, in a majority of cases, would be located in the Air Springs themselves. Air bellows undergo massive wear and tear.
- Towards the end of the Air bellow’s service life, it develops cracks that would potentially turn into a leakage
- Before removing the air bellow, you will need to depressurize it, so that it becomes saggy to help in the removal.
- Depressurization is done by accessing the air valve in the compressor and bleeding it.
Air Compressor Failure
- When loading the vehicle, and the rear suspension goes down due to the weight, the Self-Levelling mechanism should automatically start the Air Compressor and increase the Ride Height
- Sometimes, this mechanism does not work, as the Compressor does not come on
Troubleshooting Compressor Issue
- Check the Air suspension Fuses
- Check the Air Compressor Motor Relay
- In the fuse Box located in the engine bay, look for the ECAS fuse and replace concerned Fuses and Relays where necessary.
- If it still does not work, then you need to check whether the compressor is getting power supply.
- Check for voltage after loading the vehicle with 100-200 kgs weight. It should read ~ 12V
- If you find that the supply voltage is not the issue then you need to remove and examine whether the compressor itself might have burned out. Connect a 12V power supply standalone and see if it starts. If not then the compressor needs replacement.
- Before performing a compressor replacement always make sure that the ECAS fuse has been removed. Otherwise the system gets confused the next time you start the vehicle with the new compressor fitted.
Height Sensor Malfunction
- The rear of the vehicle sags at one corner
Troubleshooting Height Sensor Malfunction
- The rear suspension levelling system is triggered to self-level based on the signal from an electro-mechanical lever mechanism
- The Height sensors have oblong holes on the bracket attachment to the chassis meant for calibration adjustment
- For the Height sensors to activate the leveling mechanism, they need to be adjusted to reference ride height
- The reference ride height is the distance between the chassis frame bottom and the Bump stop bracket on the axle. The reference height is 5.33 inches with +/- 0.1 inch tolerance
- To perform the calibration the frame needs to be raised and supported on stands, and the rear axle needs to be supported on a jack for height adjustment
- The height sensor chassis bolts need to be slightly loosened so as to enable adjustment
- Adjust the chassis height to the earlier mentioned reference height.
- Now tighten the Height sensor chassis bolts
In this brief article we have discussed the different GMC Envoy Air Suspension problems, what the causes are, and Troubleshooting Tips.
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