Lexus models, including the LS sedan, RX crossover, and GX SUV, are some of the least problematic airlift vehicles on the road. In fact, most Lexus customers don’t realize that their vehicles are equipped with air suspension until something breaks.
Base
What makes most of the Lexus systems unique is the lack of a reservoir. The compressor provides air “on demand. Most systems will use four ride height sensors that measure wheel height and speed. The suspension control ECM will filter the ride altitude reading and other sensor data from the accelerometer, and even data from the engine ECU, to determine which air spring is injecting or exhausting air. The suspension control ECU will also adjust damper valves for the best ride.
The air ride system is tied to the active damping system. The system optimizes bladder spring rate and damper compression/rebound settings. It does this very quickly and can react to bumps and body movements. The driver can choose sport mode, comfort or normal. The driver can also select high and normal modes for the air suspension. In normal mode, the ride height is optimized for the road surface and vehicle speed.
If you’re jacking up the vehicle, Lexus recommends turning the engine off, on some models, so the system won’t attempt to trim the suspension. If the vehicle must be raised with the engine running, connect terminals 11 and 4 of the OBDII connector to stop the vehicle level control operation from the suspension control ECU.
Diagnostics And Sensors
When diagnosing the Lexus air ride system, it is advisable to have a scan tool that can communicate with the Suspension Control ECU, and also control modules, actuators and valves in both directions. Not having an enhanced scan tool with these functions can greatly hinder air travel repair. It is also necessary to calibrate the ride-altitude sensor.
This system uses four vehicle height sensors, as previously mentioned. It also uses acceleration sensors to measure body movement. This sensor is installed under the instrument cluster and in the trunk on the passenger side. They measure how the road surface causes bodies to move. Other inputs from the ECU, Body ECU and other modules on the CAN bus are used by the Suspension Control ECU.
Through four ride height control sensors, the Suspension Control ECU detects changes in vehicle height resulting from the number of passengers or the amount of load. Then, the Suspension Control ECU controls the level control solenoid valves, compressor and motor with dryer to automatically adjust the vehicle height to a constant level.
Checking And Testing Silencers
The motor that controls the valves inside the unit is located on the supports. These units are susceptible to damage if misused or the hood is closed with an object on it. You can remove the actuator from the stand and observe the movement of the motor as the mode is changed from the driver’s seat.
It is possible to change the actuator setting manually on the support by holding the bar in the shaft. There are five settings, which change every 30 degrees of rotation. Compress the buffer to see if the amount of force changes after making adjustments.
Air Compressor And Bladder
The compressor behind the front bumper supplies compressed air. There are two lines for the front support on the compressor. One line goes backwards and connects to a combination valve which contains a valve for the rear bladder. The Lexus system doesn’t use a reservoir to trim the suspension.
Conversion Kits
Considering the complexity of some Lexus air travel systems, system repair may not be economical for the customer. Several companies offer conversion kits that switch the vehicle to a conventional system with a passive hydraulic unit and springs.
With some replacement compressors on high-end Lexus models costing over $1,200, conversion kits may be less expensive and provide better long-term results for customers.
