ker88839_ch15.qxd
1/9/06
11:36 AM
Page 345
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.
