Automotive Electrical and Electronic Systems Classroom Manual Fifth Edition Update by John F. Kershaw

Body Accessory Systems Operation 345
Figure 15-46.
DaimlerChrysler antitheft security system. (DaimlerChrysler Corporation)
same components, and functions in essentially
the same way. Once the system is armed, any
tampering with the doors, hood, or trunk lid
signals the control module. Once triggered, the
system flashes the low-beam headlamps, the
parking lamps, and alarm indicator lamp on
and off; sounds the horn; and interrupts the
starter circuit. The system is composed of the following
components:
• Antitheft control module
• Antitheft warning indicator
• Door-key unlock switches
• Hood switch
• Trunk-lid lock-cylinder tamper switch
• Ignition-key lock-cylinder sensor
It also incorporates the following components
from other systems:
• Power door lock switches
• Door-ajar switches
• Horn relay
• Low-beam headlamps
• Parking lamps
• Keyless entry module
• Starter relay
CRUISE CONTROL
SYSTEMS
The cruise control system is one of the most popular
electronic accessories installed on today’s
vehicles. During open-road driving it can maintain
a constant vehicle speed without the continued
effort of driver. This helps reduce driver fatigue
and increases fuel economy. Several override features
built into the cruise control system allow the
vehicle to be accelerated, slowed, or stopped.
Problems with the system can vary from no operation,
to intermittent operation, to not disengaging.
To diagnose these system complaints, today’s
technicians must rely on their knowledge and ability
to perform an accurate diagnosis. Most of the
system is tested using familiar diagnostic procedures;
build on this knowledge and ability to diagnose
cruise control problems. Use system
schematics, troubleshooting diagnostics, and
switch continuity charts to assist in isolating the
cause of the fault.
Most vehicle manufacturers have incorporated
self-diagnostics into their cruise control systems.
This allows some means of retrieving trouble codes
to assist the technician in locating system faults.