Chrysler Town, Dodge Caravan. Manual - part 138

grammed into the transponder’s memory. Therefore,
blank keys for the SKIS must be programmed by the
SKIM in addition to being cut to match the mechan-
ical coding of the ignition lock cylinder. Refer to Elec-
trical,

Vehicle

Theft

Security,

Transponder

Key,

Standard Procedure - Transponder Programming.

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.

Common communication problems:
• Two transponder keys too close together.

• Speed Pass too close to transponder key.
Solid indicator that there is a system failure.
• Loss of PCM communication.

• Failed antenna circuit.

STANDARD PROCEDURE - TRANSPONDER
PROGRAMMING

USING A DRB III

T 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
Sentry Keys. When programming a blank Sentry Key
transponder, the key must first be cut to match the
ignition lock cylinder of the vehicle for which it will
be used. The vehicle’s four digit PIN code will be
required to complete this task since you will need it
to enter the Secured Access Mode in the SKIM. The
following steps must be completed using a DRB III

scan tool:

(1) Insert the blank key into the ignition and turn

it to the RUN position.

(2) Using a DRB III

t scan tool, select 9Theft

Alarm,

9 9SKIM,9 9Miscellaneous,9 and then 9Program

New Key.

(3) Enter the four digit PIN code using the DRB

III

t scan tool. When programming is completed, the

SKIM will exit Secured Access Mode and the DRB
III

t scan tool will display the results of your attempt

to program the key. One of five distinct results may
be displayed. All five are listed below:

• (Programming Successful( is displayed if the

Sentry Key programming is successful.

• (Learned Key in Ignition( is displayed if the

key in the ignition has already been programmed
into that vehicle’s SKIM.

• (Eight Keys Already Learned (At The Maxi-

mum) Programming Not Done

( is displayed if

eight keys have already been programmed into the
SKIM. In this case, if a new key needs to be added
due to a lost or defective key, the

9Erase All Keys9

command (which requires entering the Secured
Access Mode) has to be performed. Following the
9Erase All Keys9 command, all keys that will be used
to operate the vehicle MUST be reprogrammed to
the SKIM.

• (Programming Not Attempted( is displayed

after an

9Erase All Keys9 function is executed.

• (Programming Key Failed( is displayed if fur-

ther diagnosis is required.

To learn additional keys, turn the ignition OFF,

remove the learned key, insert the next new blank
key, and repeat the steps from the beginning.

“CUSTOMER LEARN” MODE

This feature is only available on domestic vehicles

or those which have a U.S. country code designator.
This procedure requires access to at least two valid
Sentry Keys. If two valid Sentry Keys are not avail-

Fig. 1 TRANSPONDER KEY - TYPICAL

1 - MOLDED CAP
2 - TRANSPONDER
3 - MOLDED CAP REMOVED
4 - SENTRY KEY

8Q - 4

VEHICLE THEFT SECURITY

TRANSPONDER KEY (Continued)

able, Sentry Key programming will require the use of
a DRB III

t scan tool.

The steps required to program Sentry Keys with

two valid Sentry Keys follows:

(1) Obtain the blank Sentry Key(s) that need to be

programmed. Cut the keys to match the ignition lock
cylinder mechanical key codes.

(2) Insert one of the two valid Sentry Keys into the

ignition switch and turn the ignition switch to the
ON position.

(3) After the ignition switch has been in the ON

position for longer than three seconds, but no more
than fifteen seconds, cycle the ignition switch back to
the OFF position. Replace the first valid Sentry Key
in the ignition lock cylinder with the second valid
Sentry Key and turn the ignition switch back to the
ON position. The second valid Sentry Key must be
inserted within 15 seconds of removing the first valid
Sentry key.

(4) About ten seconds after the completion of Step

3, the indicator light will start to flash and a single
audible chime tone will sound to indicate that the
system has entered the

9Customer Learn9 program-

ming mode.

(5) Within sixty seconds of entering the

9Customer

Learn

9 programming mode, turn the ignition switch

to the OFF position, replace the valid Sentry Key
with a blank Sentry Key transponder, and turn the
ignition switch back to the ON position.

(6) About ten seconds after the completion of Step

5, a single audible chime tone will sound and the
indicator light will stop flashing and stay on solid for
three seconds and then turn off to indicate that the
blank Sentry Key has been successfully programmed.
The SKIS will immediately exit the

9Customer

Learn

9 programming mode and the vehicle may be

started using the newly programmed Sentry Key.

These steps must be completed in their entirety for

each additional Sentry Key to be programmed. If any
of the above steps are not completed in the given
sequence, or within the allotted time, the SKIS will
exit the

9Customer Learn9 programming mode and

the programming will be unsuccessful. The SKIS will
also automatically exit the

9Customer Learn9 pro-

gramming mode if:

• It sees a non-blank Sentry Key when it should

see a blank.

• If it has already programmed eight (8) valid

Sentry Keys.

• If the ignition switch is turned to the OFF posi-

tion for more than about fifty (50) seconds.

NOTE: If you attempt to start the vehicle while in
“Customer Learn” mode (LED flashing), the vehicle

will behave as though an invalid key is being used
(i.e. the engine will stall after two (2) seconds of
running). No faults will be logged.

NOTE: Once a Sentry Key has been programmed to
a particular vehicle, it cannot be used on any other
vehicle.

VTSS/SKIS INDICATOR LAMP

DESCRIPTION

The Sentry Key Immobilizer System (SKIS) uses

an indicator light to convey information on the status
of the system to the customer. This light is shared
with the Vehicle Theft Security System (VTSS). The
light is located in the Mechanical Instrument Cluster
(MIC). The indicator light is controlled by the Body
Control Module (BCM), via Programmable Communi-
cation Interface (PCI) data bus communication with
the MIC, based upon messages it receives from the
Sentry Key Immobilizer Module (SKIM) on the PCI
data bus.

OPERATION

The Mechanical Instrument Cluster (MIC) per-

forms a four second bulb check via PCI communica-
tion

with

the

Sentry

Key

Immobilizer

Module

(SKIM). After the bulb check, the lamp is controlled
according to SKIM messages. Then, the SKIM sends
messages to the BCM to operate the light based upon
the results of the SKIS self tests. The light may be
actuated in two possible ways, flashing or on solid. If
the light comes on and stays on solid after a pow-
er-up test, this indicates that the SKIM has detected
a system malfunction. If the SKIM detects an invalid
key when the ignition switch is moved to the ON
position, it sends a message on the PCI bus to the
BCM, to flash the light. The SKIM can also send a
message to flash the light and generate a single audi-
ble chime at the same time. These two events occur-
ring simultaneously indicate that the SKIS has been
placed into the

9Customer Learn9 mode. Refer to

Electrical, Vehicle Theft Security, Transponder Key,
Standard Procedure - Transponder Programming for
more information on the

9Customer Learn9 mode. If

the light comes on and stays on after the power-up
test, diagnosis of the SKIS should be performed
using a DRB III

t scan tool and the appropriate Body

Diagnostic Procedures manual. The light is not a ser-
viceable component.

VEHICLE THEFT SECURITY

8Q - 5

TRANSPONDER KEY (Continued)

WIPERS/WASHERS

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