Installation; Transponder Key Description; Operation; Standard Procedure - Transponder Programming - Chrysler PT Cruiser Service & Repair Manual

8Q - 8 VEHICLE THEFT SECURITY
SIREN - EXPORT (Continued)
Fig. 9 SIREN LOCATION
1 - SIREN
2 - LEFT FRONT FENDER
3 - LEFT DOOR MIRROR

INSTALLATION

(1) Position siren and install retaining screws.
(2) Connect the siren electrical connector.
(3) Install air blocker in original position.
(4) Install the left front wheel well splash shield
(Refer to 23 - BODY/EXTERIOR/FRONT END
SPLASH SHIELDS - INSTALLATION).
(5) Connect the battery negative cable.
TRANSPONDER KEY
DESCRIPTION
The Sentry Key Immobilizer System (SKIS) uses a
transponder chip that is integral to each ignition key
(Fig. 10) to communicate with the Sentry Key Immo-
bilizer Module (SKIM). Ignition keys are supplied
with the vehicle when it is shipped from the factory.
The transponder chip is undermolded within the
head of the key. This undermold is hidden beneath
an overmolded rubber cap.

OPERATION

Each Sentry Key transponder has a unique tran-
sponder identification code programmed into it by the
manufacturer. The Sentry Key Immobilizer Module
(SKIM) has a unique "Secret Key" code programmed
into it by the manufacturer. When a Sentry Key
transponder is programmed into the memory of the
SKIM, the SKIM learns the transponder identifica-
tion code from the transponder, and the transponder
learns the "Secret Key" code from the SKIM. Each of
Fig. 10 SENTRY KEY IMMOBILIZER TRANSPONDER
1 - MOLDED CAP
2 - TRANSPONDER
3 - MOLDED CAP REMOVED
4 - SENTRY KEY
these codes is stored within the transponder and in
the nonvolatile memory of the SKIM. Therefore,
blank keys for the SKIS must be programmed by and
into the SKIM, in addition to being cut to match the
mechanical coding of the ignition lock cylinder. See
Sentry Key Immobilizer System Transponder Pro-
gramming in this section for more information.
The Sentry Key's transponder is within the range
of the SKIM's transceiver antenna ring when it is
inserted into the ignition lock cylinder. When the
ignition switch is turned to the ON position, the
SKIM communicates with the Sentry Key via a radio
frequency (RF) signal. The SKIM determines if a
valid key is present based on the information it
receives from the Sentry Key. If a valid key is
detected, that fact is communicated to the PCM via
the PCI bus and the vehicle is allowed to continue
running. If an invalid key is received by the PCM or
no status at all is communicated, the vehicle will
stall after two (2) seconds of running. The indicator
light will be flashing at this point. The Sentry Key's
transponder can not be repaired. If it is faulty or
damaged, it must be replaced.
STANDARD PROCEDURE - TRANSPONDER
PROGRAMMING
USING A DRB III SCAN TOOL
All Sentry Keys included with the vehicle are pre-
programmed to work with the Sentry Key Immobi-
lizer System (SKIS) when it is shipped from the
factory. The Sentry Key Immobilizer Module (SKIM)
can be programmed to recognize up to a total of eight
PT