Steering Control Module: Description and Operation

The PPS (hydraulic reaction type) controls the hydraulic pressure applied to the hydraulic reaction chamber in the gear box control unit using the PPS ECU, to change the steering force and provide optimum steering feeling at any vehicle speed and under any steering conditions.

(PPS OPERATION)
When the Ignition Switch is turned ON the starting current flows from the ECU-IG fuse to TERMINAL 4 of the PPS ECU. The PPS ECU monitors vehicle speed, input signal to TERMINAL 5 of the ECU. When the vehicle speed is low, the PPS ECU sends a higher-current from TERMINAL 1 of the ECU --> TERMINAL 1 of the solenoid valve --> TERMINAL 2 --> TERMINAL 2 of the ECU --> TERMINAL 6 --> GROUND, increasing the solenoid valve opening angle to provide comfortable steering operation. When the vehicle speed is high, the PPS ECU decreases the solenoid valve opening angle by reducing the current to the valve to provide responsive steering feeling.