GMT800. Suspension details: (2500 series, rear right). 1 - axle beam, 2 - body height sensor, 3 - sensor lever, 4 - body height sensor connector.
GMT800. suspension parts (series 1500, rear left). 1 - shock absorber, 2 - frame, 3 - shock absorber solenoid valve connector.
GMT800. suspension parts (Suburban/Yukon XL). 1 - frame, 2 - sensor connector, 3 - body height sensor (left front).
GMT800. The location of the connectors of the suspension elements. The front of the frame. 1 - shock absorber solenoid valve (left), 2 - wheel speed sensor (left), 3 - wheel speed sensor wires (left), 4 - body height sensor (left), 5 - body height sensor wires (left), 6 - chassis wire harness, 7 - shock absorber solenoid valve (right), 8 - wheel speed sensor (right), 9 - body height sensor (right), 10 - frame.
GMT800. suspension parts (2500 series, rear left). 1 - shock absorber, 2 - shock absorber solenoid valve connector, 3 - frame.
GMT800. The location of the connectors of the suspension elements. Left rear compartment (Escalade EXT). 1 - rear object sensor control unit, 2 - connector, 3 - body height control unit (ALC) and stiffness of shock absorbers (ESC), 4 - connectors, 5 - left rear seat bracket.
GMT800. The location of the connectors of the suspension elements. Right rear part of the cabin (Except Avalanche/Escalade EXT). 1 - inner side panel of the body, 2 - body wire harness, 3 - connector C1 of the control unit, 4 - connector C2 of the control unit, 5 - connector C3 of the control unit.
GMT900. Location of the control unit. 1 - right rear suspension spring, 2 - body height control unit (ALC) and stiffness of shock absorbers (ESC), 3 - frame.
GMT900. The location of the connectors of the suspension elements. Rear of the frame. 1 - body height sensor (left), 2 - body height sensor (right), 3 - frame, 4 - wheel speed sensor (right), 5 - damper solenoid valve (right), 6 - compressor of the body height control system 7 - shock absorber solenoid valve (left), 8 - wheel speed sensor (left).
GMT900. The location of the connectors of the suspension elements. The front of the frame. 1 - wheel speed sensor (right), 2 - damper solenoid valve (right), 3 - body height sensor (right), 4 - body height sensor (left), 5 - damper solenoid valve (left), 6 - wheel speed sensor (left), 7 - frame.
GMT900. Relay location. 1 - relay of the body height control system, 2 - mounting block in the engine compartment.
Description
The following systems can be installed on the vehicle. There are two Automatic Level Control systems (ALC) and Electronic Suspension Control (ESC). ALC system (automatic body leveling system) maintains the height of the body at a given level, depending on road conditions. This system only adjusts the height of the rear. And the ESC system (shock absorber stiffness system), which changes the operation parameters of all 4 shock absorbers depending on road conditions.
Both systems operate in real time. Suspension control unit (ESC) activates the solenoid valves of the suspension shock absorbers and processes the signals from the body height sensors, on cars of the 1500 series, electronic control of the stiffness of the shock absorbers (ESC) included in the body leveling system (ALC).
ALC and ESC systems control unit
The job of the ESC unit is to provide the car with a higher level of controllability (compared to suspension parameters with passive shock absorbers) both off-road and on-road driving. The control unit monitors body height, vehicle speed, steering wheel position and speed, shock absorber compression/rebound status and trailer presence switch status in real time and immediately selects "normal" or "hard" damping method for each shock absorber in order to adapt the suspension to specific driving conditions.
The suspension control unit will also use data on the position of the rear wheels relative to the body and vehicle speed to keep the height of the body at the desired level. On 1500 series models with ALC and ESC systems, the control unit will be activated approximately ten minutes after the ignition is turned off.
Self-diagnosis system and fault codes
The control unit performs system diagnostics. After four successive cycles of switching on the ignition, if there is a malfunction, the corresponding malfunction code is recorded in the memory of the unit and the message appears on the information display "SERVICE RIDE CONTROL" (suspension maintenance).
The electronic control unit enters the emergency control mode and limits the speed to 80 miles / hour (128 km/h).
Fault codes can be read using a diagnostic scanner. After diagnostics and further troubleshooting, diagnostic trouble codes must be deleted from the memory of the control unit. See chapter "Fault codes".
Body height sensors The control unit supplies a stabilized supply voltage of 5 Volts to all four body height sensors and to the air pressure sensor and receives analog signals from the sensors in the range of 0.5-4.5 V.
Shock absorbers
The shock absorber has two solenoid valves built into the piston with a winding resistance of 1.5-3.3 ohms. The response time of the shock absorber to the control signal is less than 40 milliseconds. To achieve the damping effect, the shock absorber uses the flow of the working fluid through the calibrated holes. The damper valves are controlled by the ESC unit.