mirrors and front wiper de-icer grid. In addition the
front wiper de-ice function is turned on when front
defog/defrost mode is selected.
When the defroster button is pushed, the HVAC
control sends a bus message over the PCI bus to the
Front Control Module (FCM) which controls the
Rear Window Defogger relay. The defroster LED
will illuminate when the defroster function is on.
The defroster will function for 10 minutes or can be
cycled off sooner by pressing the defroster button
again. The front wiper de-icer grid receives its 12
volts from the accessory relay through fuse 11 and
the HVAC control module supplies the grid ground.
3.20
VEHICLE THEFT SECURITY SYSTEM
The Vehicle Theft Security System (VTSS) is part
of the Body Control Module (BCM). The BCM
monitors the vehicle doors, liftgate (export only),
hood (export only), and the ignition for unautho-
rized operation. The alarm activates by sounding
the horn, flashing the headlamps and the VTSS
indicator lamp. The VTSS does not prevent engine
operation, this is done with the Sentry Key Immo-
bilizer Module (SKIM). The VTSS indicator lamp
will flash for approximately 15 seconds during the
arming process. If there is no interruption during
the arming process, upon completion the VTSS
indicator lamp will flash at a slower rate. When the
BCM receives an input to trigger the alarm, the
BCM will control the outputs of the headlamps,
horn, and VTSS lamp for approximately 15 min-
utes.
Arming (Active and Passive)
Active arming occurs when the ignition key is
removed, the RKE transmitter or door key cylinders
are used to lock the vehicle doors, whether the doors
are open or closed. The arming process is complete
only after all doors are closed.
Passive arming occurs when the ignition key is
removed, the driver door is opened, and the doors
are locked with the power door lock switch, and the
door is closed.
Disarming (Active and Passive)
Active disarming occurs when the RKE transmit-
ter is used to unlock the vehicle doors. This disarm-
ing will also halt the alarm once it has been acti-
vated.
Passive disarming occurs upon normal vehicle
entry (unlocking driver door with the key) or turn-
ing the ignition switch on with a valid skim key.
This disarming will also halt the alarm once it has
been activated.
Tamper Alert
The VTSS tamper alert will sound the horn three
times upon disarming after an initial alarming has
occurred to indicate a tamper condition has oc-
curred.
Manual Override
The system will not arm if the doors are locked
using the manual lock control or if the locks are
actuated by an inside occupant after the doors are
closed.
Diagnosis
For complaints about the Vehicle Theft Alarm
triggering on its own, use the DRBIII
t and read the
Last VTSS Cause status.
3.20.1
THATCHAM ALARM SYSTEM
(EXPORT ONLY)
The Thatcham Alarm Module monitors the vehi-
cle doors, liftgate, hood and the interior of the
vehicle for unauthorized operation. The vehicle
doors, liftgate, and hood use ajar switches as inputs
to the BCM to indicate their current status. The
interior of the vehicle is secured by the use of
Intrusion Sensors. The Intrusion Sensors are used
as inputs to the RKE/Thatcham Alarm Module to
report any motion in the interior of the vehicle. The
alarm activates by sounding the siren, flashing the
hazard lamps, and the VTSS Indicator Lamp.
Arming
Before arming, all doors, liftgate, and the hood
must be completely closed. The system can only be
armed by locking the doors with the RKE transmit-
ter.
Disarming
To disarm the alarm system, use the RKE trans-
mitter or turn the ignition on with a valid SKIM
key. This will also halt the alarm once it has been
activated.
NOTE: A powertrain control module from a
vehicle equipped with a vehicle theft security
system cannot be used in a vehicle that is not
equipped
with
a
vehicle
theft
security
system. If the VTSS indicator lamp comes on
after ignition on and stays on, the PCI Bus
Communication with the powertrain control
module has possibly been lost.
3.21
WIPER SYSTEM
3.21.1
FRONT WIPER
The front wiper/washer system consists of the
following features: lo-hi-speed, mist wipers, inter-
mittent wipers and wipe after wash. The front
wiper system is only active when the ignition switch
is in the RUN/ACC position. The vehicle operator
selects the front wiper function using the front
wiper switch (a resistive multiplexed stalk switch)
which is integral to the Multi-Function Switch. The
front wiper switch is hardwired to the Body Control
35
GENERAL INFORMATION