VAPS Circuit Operation

PURPOSE
The Variable Assist Power Steering (VAPS) System controls the amount of power assist based on vehicle speed.

A large amount of assist is provided at low speeds, when parking, for example.

A smaller amount of assist is provided at high speeds to allow greater road feel.

OPERATION
Voltage is applied to the VAPS Module through the 298 (P/O) wire when the Ignition Switch is in "RUN". The VAPS Module is grounded at ground G101 (G106 for the SHO model) through the 57 (BK) wire.

The vehicle speed signal is applied to the VAPS Module through the 563 (O/Y) and 150 (DG/W) wires.

The VAPS Module controls the position of the Variable Assist Stepper Motor through the 153 (P/Y), 154 (P/LG), 155 (GY/R), and 156 (GY/O) wires for the non SHO models. The SHO models are through the 495 (T), 496 (O), 497 (W), 498 (PK) wires.

The Variable Assist Stepper Motor controls a hydraulic valve that determines the amount of hydraulic assist available to the driver.