Chrysler Dodge Caravan 2002, Руководство пользователя

Страница: 364 / 2399

(BCM), and the DRB III
t
scan tool. The SKIM trans-
mits and receives RF signals through a tuned
antenna enclosed within a molded plastic ring forma-
tion that is integral to the SKIM housing. When the
SKIM is properly installed on the steering column,
the antenna ring fits snugly around the circumfer-
ence of the ignition lock cylinder housing. If this ring
is not mounted properly, communication problems
may arise in the form of transponder-related faults.
For added system security, each SKIM is pro-
grammed with a unique
9
Secret Key
9
code. This code
is stored in memory and is sent over the PCI bus to
the PCM and to each key that is programmed to
work with the vehicle. The
9
Secret Key
9
code is there-
fore a common element found in all components of
the Sentry Key Immobilizer System (SKIS). In the
event that a SKIM replacement is required, the
9
Secret Key
9
code can be restored from the PCM by
following the SKIM replacement procedure found in
the DRB III
t
scan tool. Proper completion of this
task will allow the existing ignition keys to be repro-
grammed. Therefore, new keys will NOT be needed.
In the event that the original
9
Secret Key
9
code can
not be recovered, new ignition keys will be required.
The DRB III
t
scan tool will alert the technician if
key replacement is necessary. Another security code,
called a PIN, is used to gain secured access to the
SKIM for service. The SKIM also stores in its mem-
ory the Vehicle Identification Number (VIN), which it
learns through a bus message from the assembly
plant tester. The SKIS scrambles the information
that is communicated between its components in
order to reduce the possibility of unauthorized SKIM
access and/or disabling.
OPERATION
When the ignition switch is moved to the RUN
position, the SKIM transmits an RF signal to the
transponder in the ignition key. The SKIM then
waits for a response RF signal from the transponder
in the key. If the response received identifies the key
as valid, the SKIM sends a
9
valid key
9
message to
the PCM over the PCI bus. If the response received
identifies the key as invalid or no response is
received from the transponder in the ignition key, the
SKIM sends an
9
invalid key
9
message to the PCM.
The PCM will enable or disable engine operation
based upon the status of the SKIM messages. It is
important to note that the default condition in the
PCM is
9
invalid key.
9
Therefore, if no response is
received by the PCM, the engine will be immobilized
after two (2) seconds of running.
The SKIM also sends indicator light status mes-
sages to the BCM to operate the light. This is the
method used to turn the light ON solid or to flash it
after the indicator light test is complete to signify a
fault in the SKIS. If the light comes ON and stays
ON solid after the indicator light test, this signifies
that the SKIM has detected a system malfunction
and/or that the SKIS has become inoperative. If the
SKIM detects an invalid key OR a key-related fault
exists, the indicator light will flash following the
indicator light test. The SKIM may also request an
audible chime if the customer key programming fea-
ture is available and the procedure is being utilized
(Refer to 8 - ELECTRICAL/VEHICLE THEFT SECU-
RITY/TRANSPONDER KEY - STANDARD PROCE-
DURE).
REMOVAL
(1) Disconnect and isolate the battery negative cable.
(2) Remove Lower Instrument Panel Cover. Refer
to Body, Instrument Panel, Lower Instrument Panel
Cover, Removal.
(3) Remove the steering column upper and lower
shrouds. Refer to Steering, Column, Column Shroud,
Removal.
(4) Disengage the steering column wire harness
from the Sentry Key Immobilizer Module (SKIM).
(5) Remove the one screws securing the SKIM to
the steering column.
(6) Rotate the SKIM upwards and then to the side
away from the steering column to slide the SKIM
antenna ring from around the ignition switch lock
cylinder housing.
(7) Remove the SKIM from the vehicle.
INSTALLATION
(1) Slip the SKIM antenna ring around the igni-
tion switch lock cylinder housing. Rotate the SKIM
downwards and then towards the steering column.
(2) Install the one screws securing the SKIM to
the steering column.
(3) Engage the steering column wire harness from
the Sentry Key Immobilizer Module (SKIM).
(4) Install the steering column upper and lower
shrouds. Refer to Steering, Column, Column Shroud,
Installation.
(5) Install the Lower Instrument Panel Cover.
Refer to Body, Instrument Panel, Lower Instrument
Panel Cover, Installation.
(6) Connect the battery negative cable.
RS
ELECTRONIC CONTROL MODULES
8E - 27
SENTRY KEY IMMOBILIZER MODULE (Continued)