The Electronic Variable Orifice (EVO) system modulates power steering effort by restricting fluid flow from pump to steering gear. Effort is varied according to vehicle speed and steering wheel rotation rate. System provides full assist at low vehicle speed for light parking effort, and minimum assist at high vehicle speed for improved handling and road feel. Full power steering assist is available for evasive maneuvers. During periods of system malfunction, system will revert to full power steering assist.
On models with air suspension, the EVO function interacts through the air suspension control module. On models without air suspension, the EVO function interacts through a separate EVO control module. Both modules are located behind center of instrument panel.
On all models, diagnostic codes are accessible through a diagnostic connector located below steering column. EVO steering system consists of vehicle speed sensor, steering wheel rotation sensor, air suspension/EVO control module, actuator solenoid valve, and wiring. Steering wheel rotation sensor and Vehicle Speed Sensor (VSS) send signals to air suspension/EVO control module, which controls EVO actuator solenoid valve as well as air suspension operation.
CONNECTOR IDENTIFICATION
Note. Use illustrations to identify connector terminals referenced in testing. (Scheme 1)and (Scheme 2)
