Infiniti QX80 Air Suspension Issues Explained(+3 Troubleshooting Tips)

In this brief article we are going to discuss the suspension issues that occur in Infiniti QX80 and what causes these failures.

The Top 4 Most Common problems with Infiniti QX80 Air Suspension are:

  • Loose and Bouncy Rear Suspension
  • Rear Lower Control Arm Rust
  • Rear Self-Levelling Air suspension not working
  • Compressor Not working

Infiniti QX80 Suspension

The Front suspension is a Double-Wishbone set-up with Coil Springs and Dual-Flow Path® twin-tube shock absorbers.

The Rear Suspension is also Double-wishbone with Coil Springs and an optional Pneumatic QX80 Self Leveling Tow Package Feature. Here, a pneumatic actuator lifts the suspension whenever it senses extra load, so that the ride-height is constant irrespective of the load variation.

The QX80’s on-road control and balance comes from the all-wheel fully independent suspension and Infiniti’s Optional proprietary Hydraulic Body Motion Control (HBMC) technology. 

The HBMC is a system that will be able to monitor body roll and lean during cornering maneuvers, and adjust specialized hydraulic cylinder actuators that are mounted to each shock absorber to help counteract lean.

Troubleshooting problems with Infiniti QX80 Air Suspension

Loose and Bouncy Rear Suspension

  • The Rear suspension feels extremely bouncy
  • Handling feels vague with a lot of roll

Troubleshooting Loose and Bouncy Rear Suspension

  • Bounciness is related to weak damping. The shock absorbers are basically unable to dampen bounce.
  • With weak rear damping, cornering ability of the vehicle is highly compromised and leads to excessive roll
  • To confirm this, you can do a bounce test.

Bounce Test:

  • At the rear of the vehicle, at any one corner, apply your weight vertically downwards in such a way that the suspension starts to bounce at that particular corner. 
  • Push downwards continuously in an oscillating motion till you now, have caused maximum vertical movement of the corner.
  • Now leave the corner and watch how many times it bounces on its own. 
  • If it takes more than one oscillation to settle, then it is confirmed that the shock absorbers have gone weak.

Rear Lower Control Arm Rust

  • Seen on 2014 model QX80’s
  • Mostly seen on vehicles that live in the Snow-Belt where there constant ice and salt on the roads
  • It is likely that the surrounding suspension components are also affected by corrosion. Be sure to check the upper control arm, Shock Absorber and Springs. Even if they are only beginning to corrode, they would fail imminently.

Rear Self-Levelling Air suspension not working

  • Rear Air Suspension Self-levelling function not working
  • Normally, after applying a load, the suspension automatically raises itself back to the normal ride height
  • Compressor running sound not heard

Troubleshooting Rear Self-Levelling Air suspension

  • Check the Air suspension Fuses
  • Check the Air Compressor Motor Relay
  • Replace Fuses and Relays where necessary.
  • Now you need to do a Self-Levelling Verification to see if it works

Self-Levelling Verification

  • Make sure there is no payload or people in the truck.
  • Measure the Ride Height from wheel center to the Fender Bottom using a Tape measure. This is the “reference ride height”.
  • Now place a load of at least 100-200 kgs in the Rear close to the rear axle position.
  • Watch whether the suspension height has changed and confirm by measuring the Ride Height from wheel center to the Fender Bottom using a Tape measure.
  • If this second value is less than the “reference ride height” then this means that the Self-Levelling Air suspension is not working at all.
  • Next, you can check whether the Ride Height Sensor is working
  • If the Ride Height Sensor Linkage is broken or bent, then this needs replacement
  • After replacement of the Ride Height Sensor, repeat the Self-Levelling Verification procedure to see if it has worked.
  • If this too did not work then it would most probably be the Air Compressor malfunctioning. (Refer to this section)
  • To Rule out the compressor, Remove the electrical connector from the Ride Height Sensor and short the 3 terminals using office binders or Safety pins and touch them together. If the Compressor is in working condition, it will start as soon as you shorted the 3 terminals. If not, then you know that it is an issue with the compressor

Compressor Not Working

  • 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
  • Replace Fuses and Relays where necessary.
  • Now you need to do a Self-Levelling Verification to see if it works
  • 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

Conclusion

In this brief article we have discussed the suspension issues that occur in Infiniti QX80 and what causes these failures.

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