diagnostic menu MERCEDES-BENZ SPRINTER 2006 Service Manual

secured to the floor under the Driver seat and
receives power from the Fuse Block No. 1. When-
ever the ignition key is turned to the run or start
position, the ACM performs a system test. The ACM
cannot be repaired or adjusted.
The microprocessor in the ACM monitors the
internal and external airbag system electrical cir-
cuits to determine the system readiness. When a
monitored system is determine to be out of range,
the ACM will set both active and stored diagnostic
trouble codes (DTC). The ACM also contains an
energy-storage capacitor. This capacitor stores
enough electrical energy to deploy the front airbag
components for two seconds following a battery
disconnect or failure during an impact.
The Accelerometer in the ACM is used to sense
the rate of vehicle deceleration, provide verification
of the direction and severity of an impact. When the
preprogrammed conditions are met, the ACM sends
an electrical signal to deploy the appropriate front
airbag system components and a deployment noti-
fication.
To provide an accident response notification, the
ACM is hardwired to the Central Timer module
(CTM) and Engine Control Module (ECM). When a
deployment occurs the ACM provides a 50ms 10.0
volt pulse to the CTM and ECM. When the Accident
Report notification signal is received the CTM un-
locks the door locks and the ECM stalls the engine.
The Accident signal will set a DTC in the CTM and
the door locks will not work until the DTC has been
erased. The ECM will set a DTC if the Accident
Report circuit is shorted to battery voltage. The
ACM saves the deployment record and after three
deployments the ACM must be replaced. The
DRBIIItcan be used to test the Accident Report
Notification feature: select the SYSTEM TEST from
the ACM main menu. Then select the Analog Crash
Output System Test.
The ACM is hardwired to the Instrument Cluster
(MIC) to control Warning Indicator (SRS indicator).
When DTCs becomes activate, the ACM illuminates
the Warning Indicator by pulling the indicator
circuit low. The SRS indicator is the only point at
which the customer can observe symptoms of a
system malfunction.
As part of the system test the ACM illuminates
the Warning Indicator on for 4.0 second bulb test.
After the lamp check, if the indicator turns off, it
means that the ACM has checked the system and
found it to be free of discernible malfunctions.
NON-CRITICAL DTCs
If the lamp comes on and stays on for a period
longer than 4.0 seconds (about 10.0 seconds) is
usually a stored DTC (intermittent problem) in the
system.
CRITICAL DTCs
DTCs that could lead to a condition where the
safety devises may not deploy or incorrectly deploy.
In the event of such a DTC, the safety of the vehicle
occupants can no longer be guaranteed. If the lamp
remains on, there could be an active DTC in the
system. Some DTCs, Internal Module and squib
DTCs, will keep the indicator illuminated even if
the codes are no longer active.
ACM NOT CONFIGURED FOR PASSENGER
AIRBAG AND TENSIONER
If after replacing the ACM the Airbag Warning
Indicator flashes continuously the ACM must be
configured for the Passenger Airbag and Tensioner.
Select Miscellaneous from the ACM main menu and
configure the Passenger Airbag Tensioner squibs.
WARNING:THE AIRBAG SYSTEM IS A
SENSITIVE, COMPLEX ELECTROMECHANICAL
UNIT. BEFORE ATTEMPTING TO DIAGNOSE OR
SERVICE ANY AIRBAG SYSTEM OR RELATED
STEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENTS YOU MUST
FIRST DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE. WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR
TO DISCHARGE BEFORE FURTHER SYSTEM
SERVICE. THIS IS THE ONLY SURE WAY TO
DISABLE THE AIRBAG SYSTEM. FAILURE TO
DO THIS COULD RESULT IN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, NEVER STRIKE OR KICK THE
AIRBAG CONTROL MODULE, AS IT CAN
DAMAGE THE IMPACT SENSOR OR AFFECT
ITS CALIBRATION.
WARNING: IF AN AIRBAG CONTROL
MODULE IS ACCIDENTALLY DROPPED
DURING SERVICE, THE MODULE MUST BE
SCRAPPED AND REPLACED WITH A NEW
UNIT. FAILURE TO TAKE THE PROPER
PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND
PERSONAL INJURY OR DEATH.
3.1.1 DRIVER AIRBAG
The airbag protective trim cover is the most
visible part of the driver side airbag system. The
airbag is mounted directly to the steering wheel.
Located under the trim cover are the airbag cushion
and the airbag cushion supporting components.
2
GENERAL INFORMATION

NOTE: Mileage will not be displayed until the IC has
been locked down.
REMOVAL
WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, seat belt
tensioner, or instrument panel component diagno-
sis or service. Disconnect and isolate the battery
negative (ground) cable, then wait two minutes for
the system capacitor to discharge before perform-
ing further diagnosis or service. This is the only
sure way to disable the supplemental restraint sys-
tem. Failure to take the proper precautions could
result in accidental airbag deployment.
CAUTION: The following procedure is for replace-
ment of an ineffective and unresponsive Instrument
Cluster (IC) with a new unit. If the IC is ineffective
or damaged but still responsive, it may be replaced
using an automatic replacement procedure that will
upload IC parameterization data from the existing IC
to the diagnostic scan tool, then download that data
to the new IC. Refer to the MISCELLANEOUS FUNC-
TIONS menu item under the IC module in the diag-
nostic scan tool, then select MODULE AUTO
REPLACEMENT and follow the scan tool prompts to
replace the IC. Do not lock down the IC until all of
the steps are followed and completed or the new IC
may be irreversibly damaged. This procedure initial-
izes and configures the IC for certain optional
equipment on the vehicle without the need for per-
forming a separate cluster programming procedure.
Failure to correctly parameterize the IC prior to it
being electronically locked down will result in the
IC being incorrectly and irreversibly configured for
improper vehicle equipment options, which will
require the IC be replaced again with another new
and unused unit to resolve.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cluster bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(3) Remove the cluster top cover from the instru-
ment panel. (Refer to 23 - BODY/INSTRUMENT
PANEL/TOP COVER - CLUSTER - REMOVAL).
(4) Remove the two screws that secure the instru-
ment cluster mounting ears to the instrument panel
base structure (Fig. 4).(5) Roll the top of the instrument cluster rearward
far enough to access and release the latch that
secures the Remote Keyless Entry (RKE)/immobilizer
module to the back of the instrument cluster rear
cover and disengage the module from the cluster
(Fig. 5).
Fig. 4 Instrument Cluster Remove/Install
1 - SCREW (2)
2 - COVER
3 - SCREW (2)
4 - INSTRUMENT CLUSTER
5 - LOOP (2)
Fig. 5 RKE/Immobilizer Module
1 - RKE/IMMOBILIZER MODULE
2-LATCH
3 - INSTRUMENT CLUSTER
8J - 8 INSTRUMENT CLUSTERVA