SPS Control Module

The speed proportional steering control module is a microprocessor-based device that monitors vehicle speed, steering wheel rpm, and controls power steering assist.
The primary functions of the module are to control SPS solenoid operation, monitor the system for proper operation, provide communication to the DRB while in diagnostic mode, and store diagnostic information in non-volatile memory.
The SPS control module monitors vehicle and steering wheel speed and uses the inputs to calculate the amount of current flow sent through the solenoid. At low speeds,the module allows full assist to the gear. As vehicle speed increase,the amount of current is increased to reduce assist. If the steering wheel speed is higher than vehicle speed, the current flow is immediately reduced to allow full assist to the driver. This allows for high-speed maneuvering. If the module power is not present or a trouble code is present, the solenoid is defaulted to the full assist position.

The module inputs include the following:
vehicle speed
steering wheel speed
fused ignition switch output
diagnostic communication

The module outputs include the following:
SPS solenoid control
diagnostic communication