key fob MERCEDES-BENZ SPRINTER 2006 Service Manual

the A-pillar. The SKREEM receives radio messages
from the RKE transmitter (fob) and sends com-
mands via the RKE Interface circuit to the CTM. If
the vehicle is equipped with VTSS, the Security
System Module will be connected in series between
the SKREEM and the CTM.
Confirmation of the RKE Lock/Unlock state is
accomplished via the turn signals. When the vehicle
is locked via RKE the turn signals will flash three
times. When it is unlocked via RKE, the turn
signals will flash one time. If the vehicle has been
unlocked via RKE and no door is opened within 40
seconds, the entire vehicle will be locked again
automatically.
If a transmitter (fob) is operated more than 255
times in succession beyond the range of the receiver
(SKREEM), the RKE portion of the key will become
inoperative. In order to put it back in synchroniza-
tion it will be necessary to have ALL the other
transmitters that are used with this vehicle avail-
able and follow the following procedure:
1. Cycle the ignition on and off 2 times within 6
seconds (leave in off position).
2. Press the lock or unlock button of the disabled
transmitter within 3 seconds of turning the
ignition off.
3. Press any button (lock or unlock) 3 more times
within 6 seconds.
4. Wait 10 seconds.
5. Press any button of ALL other transmitters
belonging to this vehicle at least once within
the next 20 seconds.
For problems related to the Immobilizer function
of the SKREEM, see Service Information.
3.5.3 AUTO DOOR LOCKS
Whenever the engine is started, the CTM receives
a message to lock all doors except the drivers door.
This is accomplished through the D+ Relay. The D+
Relay is controlled by the Instrument Cluster which
receives a command from the ECM that the engine
is running. This relay supplies power to the CTM
(for auto locking), the daytime running lamps and
the rear window defogger.
3.5.4 ACCIDENT RESPONSE
The CTM is hardwired to the Airbag Control
Module through the Enhanced Accident Report
Driver circuit. Anytime the vehicle airbags are
deployed, the CTM will unlock all doors and a
9Crash9DTC will be stored in memory. The door
locks will be inoperative until that code is cleared. If
the vehicle is severly jarred, but not enough to
deploy the airbags, it is possible that the DTC could
be set and therefore the door locks would be inop-
erable. Whenever the door locks are not opera-tional, use the DRBIII and check DTC's . If the code
9ACM has unlocked the doors9appears, use the
DRBIII and erase it.
3.6 VEHICLE THEFT SECURITY SYSTEM
(VTSS)
The Security System Module (SSM) is located
under the driver's seat. The SSM communicates
with the DRBIII over the K-line. If equipped the
Vehicle Theft Security System will monitor the
following:
²door jamb switches
²hood ajar switch
²ignition switch
²interior of the vehicle for movement
²longitudinal and transverse movement of the
vehicle
²rear defogger grids for glass breakage
²trailer connector
To arm the system the hood and all of the doors
must be closed when the vehicle is locked with the
RKE transmitter or with the use of the key in the
driver door. If the key is used, it must be held in the
lock position for 2 seconds. When the system is first
activated, the hazard lamps will flash 3 times. Also
with the system armed, the Towing/Intrusion Sen-
sor On/Off Switch indicator will flash to indicate an
armed system. To disarm the system use the RKE
or the driver door lock cylinder. Unlocking and
opening one of the other doors with the system
armed will trip the vehicle theft security system.
Interior monitoring is done by the use of an
Intrusion Sensor located in the front headliner and
with one or two sensors in the ceiling of the cargo
area depending on how the vehicle is equipped.
Monitoring of the interior of the vehicle will begin
after the system has been armed for 30 seconds. The
on/off switch located on the instrument panel can be
used to turn off this feature with the ignition switch
in either the Locked/Off or ACC position. The vehi-
cle tow-monitoring feature can also be switched off
using this switch. Re-locking the vehicle a second
time will reactivate these features.
If a trailer is connected to the vehicle when the
system is armed, the SSM will sense a resistance
change on the turn signal circuits if the trailer
harness becomes disconnected and will trip the
alarm.
Tripping the vehicle theft security system will
cause the hazard lamps to flash and the siren to
sound at 30-second intervals. The siren is equipped
with it's own self-contained battery. In the event the
vehicle's battery power is disconnected the siren
will continue to sound on it's own.
10
GENERAL INFORMATION

TRANSPONDER KEY
DESCRIPTION
The Sentry Key Immobilizer System (SKIS) which
communicates with the Sentry Key Remote Entry
Module (SKREEM), uses a transponder chip that is
integral to each key fob (Fig. 6). Ignition keys are
supplied with the vehicle when it is shipped from the
factory. The transponder chip is located within the
Remote Keyless Entry (RKE) fob.
OPERATION
Each Sentry Key has a unique transponder identi-
fication code permanently programmed into it by the
manufacturer. Likewise, the Sentry Key Remote
Entry Module (SKREEM) has a unique ªSecret Key9
code programmed into it by the manufacturer as
well. When a Sentry Key is programmed into the
memory of the SKREEM, the SKREEM stores the
transponder identification code from the Sentry Key,
and the Sentry Key learns the ªSecret Keyº code
from the SKREEM. Once the Sentry Key learns the
ªSecret Keyº code of the SKREEM, it is also perma-
nently programmed into the transponder's memory.
The Sentry Key's transponder is within the range
of the SKREEM's transponder ring when it is
inserted into the ignition lock cylinder. When the
ignition switch is turned to the ON position, the
SKREEM communicates with the Sentry Key via a
radio frequency (RF) signal. The SKREEM deter-
mines if a valid key is present based on the informa-
tion it receives from the Sentry Key. If a valid key is
detected, that fact is communicated to the Engine
Control Module (ECM) via the Controller Area Net-
work (CAN) data bus and the vehicle is allowed to
continue running. If an invalid key is received by theECM or no status at all is communicated, the vehicle
will stall after two (2) seconds of running. The indi-
cator 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:
²Two transponder keys too close together.
²Speed Pass too close to transponder key.
Solid indicator that there is a system failure.
²Loss of ECM communication.
²Failed transponder ring circuit.
Fig. 6 TRANSPONDER KEY
1 - TRANSPONDER KEY FOB
2 - RKE BUTTONS
3 - INDICATOR LIGHT
4 - KEY BLADE RELEASE BUTTON
5 - KEY BLADE
VAVEHICLE THEFT SECURITY 8Q - 5