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

344 Chapter Fifteen
Figure 15-45.
PASS-Key circuit diagram. (GM Service and Parts Operations)
If the key resistor code and the module’s fixed
resistance value do not match, the module shuts
down for two to four minutes. Repeating the
attempt to start the vehicle with the wrong key
will result in continued module shutdowns.
During vehicle operation, the key resistor pellet
inputs are continually read. If the module sees an
open, short, or incorrect resistance value for
60 consecutive seconds, a Security indicator lamp
comes on and remains lighted until the fault is
corrected. The lamp also comes on for five seconds
when the ignition is first turned on. This
serves as a bulb check and indicates that the system
is functioning properly.
DaimlerChrysler Antitheft
Security System
This passive-arming theft-deterrent system
(Figure 15-46) is factory installed on high-line
Chrysler models and functions like many aftermarket
alarm installations. When combined with
the Remote Keyless Entry (Figure 15-40), the
system becomes an active arming system. Once
armed, the doors, hood, and trunk lid all are monitored
for unauthorized entry.
The system is passively armed by activating the
power door locks before closing the driver’s door;
it will not arm if the doors are locked manually.
The system is actively armed if the doors are
locked with the RKE transmitter. A SET lamp in
the instrument cluster flashes for 15 seconds during
the arming period. If a forcible entry is
attempted while the system is armed, it responds
by sounding the horn, flashing the park and taillamps,
and activating an engine kill feature.
The system is passively disarmed by unlocking
either front door with the key, or actively disarmed
by using the RKE transmitter. If the alarm
has been activated during the driver’s absence,
the horn will blow three times when the vehicle is
disarmed as a way of informing the driver of an
attempted entry or tampering.
Ford Antitheft System
This antitheft system bears many similarities to
the Delco UTD theft-deterrent system. It is
installed on luxury models, uses many of the