Chapter 21 Chassis System Electronics 405
Copyright by Goodheart-Willcox Co., Inc.
Figure 21-14. Study the major parts of an electric assist power steering system. (Honda Motor Co.)
Under-Hood Fuse Relay Box
Data Link
Connector (DLC)
Battery
Steering ECM
Rack-and-Pinion
Assembly
Motor
Under-Dash
Fuse Relay Box
Gauge Control
Module (TACH)
EPS Indicator
Since the time between sending a pulse and the time
it takes for the pulse to bounce off objects, the ECM can
calculate the distance between the car and the object. Four
ultrasonic or video sensors are mounted in the four corners
of the bumpers. They all work together to allow the ECM to
move, steer, and stop the vehicle when parking.
Electronic Height Control
An electronic height control system uses a height
sensor to control the operation of a small electric air com-
pressor. This type of system is used on the rear of the car to
compensate for loads placed in the trunk or when passengers
fi ll the back seat. These parts include:
Height sensor—lever-operated switch that reacts to
changes in car body height and suspension movement.
Compressor assembly—electric motor-powered air
pump that produces pressure for the system.
Pressure lines—air hoses that connect the compressor
with air shock absorbers.
Air shocks—air-filled shock absorbers that can act on the
suspension system to alter the ride height of the car.
Sensor link—linkage rods that connect the height sen-
sor to the suspension system.
Solenoid valve—solenoid-operated air valve that can
release air pressure from the system.