Universal Theft Deterrent System
The Universal Theft Deterrent (UTD) system is standard equipment on
this vehicle. UTD provides an audible warning (using the vehicle horns) and/or
lights in the event of an unauthorized entry through the doors, hatch/trunk
or hood (export). The UTD is an internal function of the BCM which
utilizes PASS-Key®, serial data , and various switch input
information to perform UTD functions. The Powertrain Control Module
(PCM) controls the fuel enable circuit. The BCM must exchange
a unique password with the PCM to allow fuel enable processing
to occur. If the BCM detects an illegal intrusion, the BCM will disable
cranking and the PCM will not allow fuel delivery to the fuel injectors.
BCM Inputs/Outputs
The BCM receives input information from various systems to determine
what state of the UTD system should be in. The BCM can receive this information
from either a direct input (hard wired) or from the serial data
line. Refer to
Theft Deterrent Diagnostic Information
on how the BCM receives UTD inputs.
Inputs
The BCM monitors the following inputs affecting UTD:
• | Driver door ajar switch |
• | Passenger door ajar switch |
• | Driver power door lock/unlock switch |
• | Hood ajar switch (export only) |
• | Passenger power door lock/unlock switch |
• | Driver door lock cylinder switch |
• | Passenger door lock cylinder switch |
Outputs
The BCM controls the following outputs for UTD:
• | Theft deterrent relay (starter enable) |
• | Password exchange with the PCM (fuel enable) |
BCM Interface with Remote Function Actuation (RFA) System
The RFA system interacts with the UTD system (part of the BCM operation)
in the following ways:
• | RFA system sends a UNLOCK (passive or active) message on the serial
data line to the BCM. |
• | Upon receiving a UNLOCK message from the RFA system, the BCM turns
the courtesy lamps ON (if ambient light is low) and disarms the UTD system. |
• | Upon receiving an LOCK message on the serial data line from RFA
system, the BCM turns the courtesy lamps OFF, and momentarily sounds the horn
and/or flashes the lights (depending on selected personalize
options) to indicate security system arming. |
Arming the UTD System
When one door, both doors or the hatch is opened, the SECURITY indicator
on the instrument panel flashes as a reminder to arm the system. If after
10 minutes the door or hatch has not been closed,
the flashing SECURITY indicator will turn OFF.
To arm the UTD system perform the following steps:
- Turn OFF the ignition switch.
- With the driver or passenger door open, press one of the power
door lock switches. OR
- Press the LOCK button on the remote transmitter or walk out of
range with the passive switch ON.
This puts the UTD system in the active mode, where it has detected that
the arming request has been made, but the vehicle is not yet secured (i.e.
both doors are not shut). This state is indicated by the
SECURITY indicator changing from flashing to ON continuously.
If the vehicle is not secured after 10 minutes,
the SECURITY indicator is turned OFF. It is important to
note that the system will not be armed if the doors are locked
manually; the power door lock switch or remote control transmitter
(RFA) system must be used.
When the power lock switch or remote transmitter has been activated
and both doors and the hatch are closed, the UTD is in the Doors and Hatch
Armed State. In this mode, the UTD is monitoring for an illegal
intrusion into the vehicle through the doors or hatch.
This is the most common armed state of the UTD, as it represents
the usual state of a driver leaving the vehicle with the
security system set.
When the power lock switch has been activated and both doors are closed,
but the hatch is open, the UTD is in the Doors Armed State. In this state,
the UTD is monitoring for an illegal intrusion into the
vehicle through the doors. If the hatch is closed, the
change in state of the hatch ajar switch will not be considered
an intrusion, and the alarm will not be activated. If the
hatch is not closed, the UTD system will remain in the doors
armed mode and will ignore the hatch ajar switch input and the
SECURITY indicator will go out.
Activating the UTD System
An illegal intrusion is defined as activity on any one of the following
BCM inputs without the BCM first noting proper disarming of the UTD system:
• | Driver door ajar switch |
• | Passenger door ajar switch |
• | Turn ON the ignition switch (with an invalid PASS Key Detected) |
• | Hood ajar switch (export only) |
• | Power door unlock switch |
If the BCM senses an intrusion it enters alarm mode. The BCM sounds
the vehicle horns and/or flashes the lights (depending on selected personalize
options) at approximately once a second,
disables engine cranking through the PASS-Key®
system, and the PCM disables fuel delivery. The alarm
mode is active for approximately 2 minutes (30 seconds
export) with the ignition and fuel system
disabled. This is followed by a 3 minute
time-out with the horn no longer active. If no new intrusions
are detected after the time-out, the horn
is kept OFF. The system must be disarmed
or the intrusion condition removed after the time-out for the system
to exit alarm mode and the BCM to re-enable
the ignition and PCM re-enable the fuel system.
Disarming the UTD System
The UTD system is normally disabled by unlocking the door by using the
door lock cylinder or remote transmitter. This allows normal owner entry
into the vehicle without setting off the alarm.
To disarm the UTD system perform the following steps:
- Insert the key in the door lock cylinder and rotate it as if normally
unlocking the door.
- Insert the correct Pass-Key® into the ignition lock cylinder
on the steering column and turn ON the ignition switch.
- Press the UNLOCK button on the remote transmitter or walk into
range with the passive switch ON.
It is important to note that, somewhat like not being able to arm the
system using the manual lock switch, manually unlocking the doors will not
disable the UTD alarm mode. Also, using the power door unlock
switch will not disable UTD alarm mode. Disconnecting the battery
or pulling fuses will not disable alarm mode, since the BCM stores
the theft deterrent status in the EEPROM, and will go back into
alarm mode when the battery is reconnected. Only the three actions
described above will successfully disarm UTD alarm mode.
Personal Automotive Security (PASS-Key®) System
The PASS-Key® system is a subsystem function of the BCM, which operates
using an ignition key with one of 15 resistor pellets embedded in the key.
The BCM samples the resistor pellet when the ignition is turned
to the ON position. The BCM compares the resistor value in the
key to a resistive window to which the PASS-Key® system has
been programmed; refer to
PASS-Key Programming
. If the resistance of the key does not fit into
the programmed window resistance, the BCM will not activate the
vehicle theft deterrent relay, the steering column will remain LOCKED,
and the PCM will disable fuel by disabling the fuel injectors.
The PASS-Key® system operates independently of the UTD system;
it provides protection even if the UTD system is not armed. However,
when UTD is armed and enters alarm mode, the BCM disables cranking
and PCM disable fuel delivery. The PASS-Key® system also will
disarm the UTD system from its armed or alarm modes if the ignition
key with the proper resistor pellet is inserted into the ignition
lock cylinder and the ignition is turned ON.
PASS-Key® System Components
BCM
The PASS-Key® system is a subsystem of the BCM. The BCM provides
all the logic necessary to operate the PASS-Key® system. The BCM uses
direct input information from other systems or components to determine
the status of the PASS-Key® system. The BCM controls its output
functions based on PASS-Key® status.
PCM
The PASS-Key® fuel enable function is provided by the PCM. When
the BCM detects a PASS-Key® resistance value, the BCM and PCM must exchange
the correct password in order for the PCM to enable fuel.
Ignition Cylinder and Key
The ignition is used by the PASS-Key® system to determine if the
correct key is being used to start the vehicle. When the ignition is first
turned ON, the BCM measures the key resistance
through the sensing contacts located in
the ignition switch.
Steering Column Lock
The PASS-Key® system is able to provide steering column LOCK functions.
The BCM provides output control allowing the BCM to LOCK or UNLOCK the steering
column
electronically based on PASS-Key® status.
Theft Deterrent Relay
The PASS-Key® system can disable engine cranking through the theft
deterrent relay. When the BCM detects the correct PASS-Key® resistance
value,
the BCM grounds the theft deterrent relay coil circuit, which allows
the engine to
be cranked.
PASS-Key® System Inputs/Outputs
Inputs
The BCM monitors the following as inputs affecting PASS-Key® system:
Outputs
The BCM controls the following outputs for PASS-Key®
• | Password exchange with the PCM (fuel enable). |
• | Steering column lock motor |
PASS-Key® Time-Out
When the PASS-Key® system detects an invalid key, the PASS-Key®
system disables cranking and fuel enable for a time-out period of approximately
3 minutes. If a key is inserted or the ignition is turned
ON before the 3 minute time-out is complete, the
timer will reset to 3 minutes. Disconnecting the
battery or pulling fuses will not disable the time-out;
the BCM stores the PASS-Key® state in EEPROM, and will restart
the minute timer when the battery is reconnected. Even
if the proper resistance key is inserted during the time-out
the vehicle will not start until the total time period
has expired.
Fuel Enable
The BCM and PCM operate in conjunction with each other to determine
fuel enable. The fuel enable system uses a password exchange between the
BCM and PCM after a correct PASS-Key® has been sampled
by the BCM. The serial data line is used to communicate
this password information from the BCM to the PCM. When
the BCM stored password, is sent to the PCM over the serial
data line, the PCM checks if the password matches its own stored
password. If the password matches, the PCM will enable fuel
delivery. If the password does not match, the PCM will disable
fuel delivery and store a DTC.