2005 MERCEDES-BENZ SPRINTER horn

GROUP TAB LOCATOR
Introduction
0Lubrication & Maintenance
2Suspension
3Differential & Driveline
5Brakes
7Cooling
8AAudio/Video
8BChime/Buzzer
8EElectronic Control Modules
8FEngine Systems
8GHeated Systems
8HHorn
8IIgnition Control
8JInstrument Cluster
8LLamps
8NPower Systems
8ORestraints
8PSpeed Control
8QVehicle Theft Security
8RWipers/Washers
8WWiring
9Engine
11Exhaust System
13Frame & Bumpers
14Fuel System
19Steering
21Transmission
22Tires/Wheels
23Body
24Heating & Air Conditioning
25Emissions Control
Component and System Index
Service Manual Comment Forms (Rear of Manual)

INTERNATIONAL SYMBOLS
DESCRIPTION
The graphic symbols illustrated in the following
International Control and Display Symbols Chart
(Fig. 1) are used to identify various instrument con-
trols. The symbols correspond to the controls and dis-
plays that are located on the instrument panel.
FASTENER IDENTIFICATION
DESCRIPTION
The SAE bolt strength grades range from grade 2
to grade 8. The higher the grade number, the greaterthe bolt strength. Identification is determined by the
line marks on the top of each bolt head. The actual
bolt strength grade corresponds to the number of line
marks plus 2. The most commonly used metric bolt
strength classes are 9.8 and 10.9. The metric
strength class identification number is imprinted on
the head of the bolt. The higher the class number,
the greater the bolt strength. Some metric nuts are
imprinted with a single-digit strength class on the
nut face. Refer to the Fastener Identification and
Fastener Strength Charts (Fig. 2) and (Fig. 3).
Fig. 1 INTERNATIONAL CONTROL AND DISPLAY SYMBOLS
1 High Beam 13 Rear Window Washer
2 Fog Lamps 14 Fuel
3 Headlamp, Parking Lamps, Panel Lamps 15 Engine Coolant Temperature
4 Turn Warning 16 Battery Charging Condition
5 Hazard Warning 17 Engine Oil
6 Windshield Washer 18 Seat Belt
7 Windshield Wiper 19 Brake Failure
8 Windshield Wiper and Washer 20 Parking Brake
9 Windscreen Demisting and Defrosting 21 Front Hood
10 Ventilating Fan 22 Rear hood (Decklid)
11 Rear Window Defogger 23 Horn
12 Rear Window Wiper 24 Lighter
2 INTRODUCTIONVA

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
CENTRAL TIMER MODULE
DESCRIPTION..........................1
OPERATION............................2
DIAGNOSIS AND TESTING - CENTRAL TIMER
MODULE.............................2
REMOVAL.............................2
INSTALLATION..........................2
CONTROLLER ANTILOCK BRAKE
DESCRIPTION..........................3
REMOVAL.............................3INSTALLATION..........................3
ENGINE CONTROL MODULE
DESCRIPTION..........................3
REMOVAL.............................4
INSTALLATION..........................4
TRANSMISSION CONTROL MODULE
DESCRIPTION..........................5
OPERATION............................5
STANDARD PROCEDURE - TCM ADAPTATION . 8
CENTRAL TIMER MODULE
DESCRIPTION
The central timer module (CTM) is located beneath
the driver seat. The CTM uses information carried on
the programmable communications interface (PCI)
data bus network along with many hard wired inputs
to monitor many sensor and switch inputs. In
response to those inputs, the circuitry and program-
ming of the CTM allow it to supply the vehicle occu-
pants with audible and visual information, and to
control and integrate many functions and features of
the vehicle through both hard wired outputs and the
transmission of message outputs to other modules in
the vehicle over the PCI data bus.
The features that the CTM supports or controls
include the following:
²Central Locking- The CTM on vehicles
equipped with the optional Vehicle Theft Security
System (VTSS) includes a central locking/unlocking
feature.
²Enhanced Accident Response- The CTM pro-
vides an optional enhanced accident response fea-
ture. This is a programmable feature.
²Panic Mode- The CTM provides support for
the optional RKE system panic mode including horn,
headlamp, and park lamp flash features.
²Power Lock Control- The CTM provides the
optional power lock system features, including sup-
port for the automatic door lock and door lock inhibit
modes.²Programmable Features- The CTM provides
support for certain programmable features.
²Remote Keyless Entry- The CTM provides
the optional Remote Keyless Entry (RKE) system fea-
tures, including support for the RKE Lock (with
optional horn and park lamps flash), Unlock (with
park lamps flash, driver-door-only unlock, and
unlock-all-doors), Panic, and illuminated entry
modes, as well as the ability to be programmed to
recognize up to four RKE transmitters. The RKE
horn, driver-door-only unlock, and unlock-all-doors
features are programmable.
²Vehicle Theft Security System- The CTM
provides control of the optional Vehicle Theft Secu-
rity System (VTSS) features, including support for
the central locking/unlocking mode and control of the
Security indicator in the instrument cluster.
Hard wired circuitry connects the CTM to the elec-
trical system of the vehicle. Refer to the appropriate
wiring information.
Many of the features in the vehicle controlled or
supported by the CTM are programmable using the
DRBIIItscan tool. However, if any of the CTM hard-
ware components are damaged or faulty, the entire
CTM unit must be replaced. The hard wired inputs
or outputs of all CTM versions can be diagnosed
using conventional diagnostic tools and methods;
however, for diagnosis of the CTM or the PCI data
bus, the use of a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
VAELECTRONIC CONTROL MODULES 8E - 1

HORN
TABLE OF CONTENTS
page page
HORN
REMOVAL.............................1
INSTALLATION..........................1HORN SWITCH
REMOVAL.............................1
INSTALLATION..........................1
HORN
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the wire harness connectors.
(3) Remove the mounting fastener and horns.
INSTALLATION
(1) Position horns and install mounting fasteners.
(2) Connect wire harness connector.
(3) Connect battery negative cable.
HORN SWITCH
REMOVAL
(1) Disconnect and isolate the battery negative
cable.(2) Remove the drivers side airbag (Refer to 8 -
ELECTRICAL/RESTRAINTS/DRIVER AIRBAG -
REMOVAL).
(3) Remove the electrical harness connector.
(4) Remove the mounting fasteners and horn
switch.
INSTALLATION
(1) Connect the wire harness connector.
(2) Position the horn switch and install the mount-
ing fasteners.
(3) Install the drivers side airbag (Refer to 8 -
ELECTRICAL/RESTRAINTS/DRIVER AIRBAG -
INSTALLATION).
(4) Connect the battery negative cable.
VAHORN 8H - 1

FRONT FOG LAMPS
Vehicles equipped with optional front fog lamps
have a front fog lamp relay installed in a relay
bracket located below the forward edge of the driver
side front seat cushion within the driver side front
seat riser, a fog lamp switch installed in the cluster
bezel on the instrument panel outboard of the steer-
ing column, and a fog lamp bulb installed in each of
the two front lamp units. The front fog lamps have a
path to ground at all times through their connection
to the vehicle wire harness. The headlamp switch cir-
cuitry of the left (lighting) control stalk of the multi-
function switch controls front fog lamp operation by
providing battery current to the front fog lamp relay
only when the low beam headlamps are selected. The
fog lamp switch controls front fog lamp operation by
energizing or de-energizing the front fog lamp relay
control coil.
HAZARD WARNING LAMPS
With the hazard switch in the On position, the
hazard switch button illuminates and the right and
left turn signal indicators as well as the right and
left turn signal lamps begin to flash on and off. When
the hazard warning system is activated, the hazard
switch circuitry within the multi-function switch and
the wipers, turn signals and engine start control
module electronic circuitry within the fuse block will
repeatedly energize and de-energize the turn signal
relay located in the fuse block. The turn signal relay
switches battery current from a fused B(+) fuse in
the fuse block to the turn signal indicators and the
turn signal lamps. The flashing of the hazard switch
button illumination lamp is also controlled by the
output from the turn signal relay.
HEADLAMPS
The headlamp system includes the exterior lighting
switches integral to the left (lighting) control stalk of
the multi-function switch as well as the low and high
beam bulbs installed in the right and left front lamp
units (Fig. 1). The headlamp bulbs have a path to
ground at all times through the vehicle wire harness.
The exterior lighting switches control headlamp oper-
ation by providing battery current to the selected low
or high beam bulbs. Each front lamp unit includes
two integral adjustment screws to be used for static
horizontal and vertical aiming of the headlamp beam
reflectors.
HEADLAMP LEVELING
The headlamp leveling system includes a leveling
actuator motor integral to each front lamp unit, and
a rotary thumbwheel actuated headlamp leveling
switch in the cluster bezel on the instrument panel
outboard of the steering column. The headlamp lev-eling system allows the headlamp beam reflectors to
be adjusted to one of four vertical positions to com-
pensate for changes in inclination caused by the load-
ing of the vehicle suspension. The actuator motors
are mechanically connected through an integral
pushrod to an adjustable headlamp reflector. The
headlamp leveling switch is a resistor multiplexed
unit that provides one of four voltage outputs to the
headlamp leveling motors. The headlamp leveling
motors will move the headlamps to the selected posi-
tion based upon the voltage input received from the
switch. The headlamp leveling motors and switch
have a path to ground at all times. The headlamp
leveling components operate on battery current
received through the park lamps circuit so that the
system will only operate when the exterior lighting is
turned on.
PARK LAMPS
The park lamps system includes the exterior light-
ing switches integral to the left (lighting) control
stalk of the multi-function switch (Fig. 1), the front
park/side marker lamps, the front position lamps, the
rear park lamps, the rear side marker lamps, the
optional clearance lamps, and the license plate
lamps. Each of these lamps are provided with a path
to ground at all times through the vehicle wire har-
ness. The exterior lighting switches control the park
lamp operation by providing battery current through
the park lamps circuit to the appropriate lamp bulbs.
TURN SIGNAL LAMPS
When the left (lighting) control stalk of the multi-
function switch is activated (Fig. 1), the turn signal
Fig. 1 Lighting Switch
1 - LEFT TURN SIGNAL
2 - RIGHT TURN SIGNAL
3 -EXTERIOR LIGHTING
4 - BEAM SELECT (DIMMER)
5 - OPTICAL HORN
8L - 4 LAMPS/LIGHTING - EXTERIORVA
LAMPS/LIGHTING - EXTERIOR (Continued)

(1) Reconnect and latch the vehicle wire harness
connector for the ACM to the ACM connector recep-
tacle located on the left facing side of the module
(Fig. 12).
(2) Carefully position the ACM cover base plate
onto the mounting bracket that is welded onto the
floor panel under the driver side front seat (Fig. 13).
(3) Carefully position the ACM onto the ACM cover
base plate. When the ACM is correctly positioned, the
three ACM mounting tabs will be aligned with the
holes in the cover base plate and the mounting
bracket, and the orientation arrow on the ACM label
will be pointed forward in the vehicle.
(4) Install and tighten the three screws that secure
the ACM to the mounting bracket that is welded onto
the floor panel within the driver side front seat riser.
Be certain that the ground eyelet terminal is
installed under the screw for the left rear mounting
tab. Tighten the screws to 12 N´m (105 in. lbs.).
(5) Position the ACM cover over the ACM and
press it down firmly and evenly until it snaps into
position over the ACM cover base plate (Fig. 11).
(6) Position the control module bracket onto the
top of the driver side seat riser (Fig. 10).
(7) Install and tighten the two screws that secure
the control module bracket to the top of the seat riser
under the driver side front seat. Tighten the screws
to 2 N´m (18 in. lbs.).
(8) Position the cover panel onto the top of the
driver side seat riser (Fig. 9).
(9) Install and tighten the two screws that secure
the cover panel to the top of the seat riser under the
driver side front seat. Tighten the screws to 2 N´m
(18 in. lbs.).(10) Move the driver side front seat back to its
driving position.
(11) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
NOTE: If the Airbag Control Module (ACM) has been
replaced with a new unit, it will be necessary to ini-
tialize the new ACM. In order to function properly,
the ACM must be programmed for the correct stan-
dard and optional supplemental restraint system
components installed in the vehicle. To initialize the
ACM, a DRBIIITscan tool is required. Refer to the
appropriate diagnostic information.
CLOCKSPRING
DESCRIPTION
The clockspring assembly is secured with two
screws onto the multi-function switch housing near
the top of the steering column directly below the
steering wheel (Fig. 14). The clockspring consists of a
flat, round molded plastic case that contains a spool-
like molded plastic rotor with a large exposed hub
covering the entire upper surface of the case. The
rotor hub has a large center hole that is internally
ribbed to engage splines on the upper steering col-
umn shaft, and two small clearance holes that pro-
Fig. 13 ACM Cover Base Plate
1 - BASE PLATE
2 - SEAT RISER
3 - GROUND EYELET TERMINAL
4 - ACM CONNECTOR
5 - FLOOR PANEL
Fig. 14 Clockspring
1 - PIGTAIL WIRE CONNECTOR (2)
2 - CASE
3 - CANCEL CAM
4 - ROTOR
5 - SCREW (2)
6 - HORN SWITCH CONNECTOR (2)
7 - AIRBAG CONNECTOR
8O - 12 RESTRAINTSVA
AIRBAG CONTROL MODULE (Continued)

vide access to the case mounting screws. The lower
side of the rotor hub also serves as an integral
molded plastic turn signal cancel cam.
A single connector receptacle on the upper surface
of the rotor has pigtail wires that connect to the horn
switch and the driver airbag on the steering wheel,
while a single connector receptacle on the lower sur-
face of the case has pigtail wires that connect the
clockspring to the vehicle wire harness on the steer-
ing column. Within the plastic case and wound
around the rotor spool is a long ribbon-like tape that
consists of several thin copper wire leads sandwiched
between two thin plastic membranes. The outer end
of the tape terminates at the connector receptacle
that faces the steering column, while the inner end of
the tape terminates at the connector receptacle on
the hub of the clockspring rotor that faces the steer-
ing wheel.
Service replacement clocksprings are shipped pre-
centered and with the mounting screws backed out
from the case far enough to engage the access holes
in the upper surface of the rotor. The mounting
screws secure the centered clockspring rotor to the
clockspring case during shipment, but allow free
rotation of the rotor once the clockspring is properly
installed on the steering column. (Refer to 8 - ELEC-
TRICAL/RESTRAINTS/CLOCKSPRING - STAN-
DARD PROCEDURE - CLOCKSPRING
CENTERING).
The clockspring cannot be repaired. If the clock-
spring is faulty, damaged, or if the driver airbag has
been deployed, the clockspring must be replaced.
OPERATION
The clockspring is a mechanical electrical circuit
component that is used to provide continuous electri-
cal continuity between the fixed vehicle wire harness
and the electrical components mounted on or in the
rotating steering wheel. On this model the rotating
electrical components include the driver airbag and
the horn switch. The clockspring case is positioned
and secured to the multi-function switch housing
near the top of the steering column. The connector
receptacle on the underside of the fixed clockspring
case connects the clockspring to the vehicle electrical
system through two take outs with connectors from
the vehicle wire harness.
The clockspring rotor is movable and is keyed by
integral molded ribs on the inner circumference of
the rotor hub to the splines on the external circum-
ference of the upper steering column shaft. The two
integral lobes of the turn signal cancel cam formation
on the lower surface of the clockspring rotor hub con-
tact the turn signal cancel actuator of the multi-func-
tion switch to provide automatic turn signal
cancellation. The yellow sleeved pigtail wire on theupper surface of the clockspring rotor connects the
clockspring to the driver airbag, while two single pig-
tail wires connect to the feed and ground terminals of
the horn switch located within the hub cavity of the
steering wheel.
Like the clockspring in a timepiece, the clockspring
tape has travel limits and can be damaged by being
wound too tightly during full stop-to-stop steering
wheel rotation. To prevent this from occurring, the
clockspring is centered when it is installed on the
steering column. Centering the clockspring indexes
the clockspring tape to the movable steering compo-
nents so that the tape can operate within its
designed travel limits. However, if the clockspring is
removed from the steering column or if the steering
shaft is disconnected from the steering gear, the
clockspring spool can change position relative to the
movable steering components. The clockspring must
be re-centered following completion of this service or
the tape may be damaged.
Service replacement clocksprings are shipped pre-
centered and with the mounting screws backed out
from the case far enough to engage the access holes
in the upper surface of the rotor. The mounting
screws secure the centered clockspring rotor to the
clockspring case during shipment, but allow free
rotation of the rotor once the clockspring is properly
installed on the steering column. The clockspring
mounting screws should not be tightened into the
clockspring case until the clockspring has been
installed on the steering column. If the screws are
tightened into or removed from the case before the
clockspring is installed on a steering column, the
clockspring centering procedure must be performed.
(Refer to 8 - ELECTRICAL/RESTRAINTS/CLOCK-
SPRING - STANDARD PROCEDURE - CLOCK-
SPRING CENTERING).
STANDARD PROCEDURE - CLOCKSPRING
CENTERING
The clockspring is designed to wind and unwind
when the steering wheel is rotated, but is only
designed to rotate the same number of turns (about
six to seven complete rotations) as the steering wheel
can be turned from stop to stop. Centering the clock-
spring indexes the clockspring tape to other steering
components so that it can operate within its designed
travel limits. The rotor of a centered clockspring can
be rotated three to three and one-half turns in either
direction from the centered position, without damag-
ing the clockspring tape.
However, if the clockspring is removed for service
or if the steering column is disconnected from the
steering gear, the clockspring tape can change posi-
tion relative to the other steering components. The
clockspring must then be re-centered following com-
VARESTRAINTS 8O - 13
CLOCKSPRING (Continued)

pletion of such service or the clockspring tape may be
damaged. Service replacement clocksprings are
shipped pre-centered and with the mounting screws
backed out from the case far enough to engage the
access holes in the upper surface of the rotor (Fig.
15). The clockspring mounting screws should not be
tightened into the clockspring case until the clock-
spring has been installed on the steering column. If
the screws are tightened into or removed from the
case before the clockspring is installed on a steering
column, the clockspring centering procedure must be
performed.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BAT-
TERY NEGATIVE (GROUND) CABLE, THEN WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
NOTE: Before starting this procedure, be certain to
turn the steering wheel until the front wheels are in
the straight-ahead position.
(1) Place the front wheels in the straight-ahead
position.(2) Remove the clockspring from the steering col-
umn. (Refer to 8 - ELECTRICAL/RESTRAINTS/
CLOCKSPRING - REMOVAL).
(3) Tighten the two clockspring mounting screws
all the way into the clockspring case.
(4) Rotate the clockspring rotor counterclockwise
to the end of its travel.Do not apply excessive
torque.
(5) From the end of the counterclockwise travel,
rotate the rotor about three to three and one-half
turns clockwise, until the clearance holes in the
clockspring rotor are aligned with the two mounting
screws in the clockspring case. The clockspring is
now centered.
(6) Loosen the two clockspring mounting screws
far enough so that they extend into the clearance
holes in the upper surface of the clockspring rotor,
preventing the rotor from changing position relative
to the clockspring case.
(7) The front wheels should still be in the straight-
ahead position. Reinstall the clockspring onto the
steering column. (Refer to 8 - ELECTRICAL/RE-
STRAINTS/CLOCKSPRING - INSTALLATION).
REMOVAL
The clockspring cannot be repaired. It must be
replaced if faulty or damaged, or if the driver airbag
has been deployed.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. DISCONNECT AND ISOLATE THE BAT-
TERY NEGATIVE (GROUND) CABLE, THEN WAIT
TWO MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE PERFORMING FURTHER
DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE
WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
NOTE: Before starting this procedure, be certain to
turn the steering wheel until the front wheels are in
the straight-ahead position.
(1) Place the front wheels in the straight ahead
position.
(2) Remove the driver airbag from the steering
wheel. (Refer to 8 - ELECTRICAL/RESTRAINTS/
DRIVER AIRBAG - REMOVAL).
Fig. 15 Clockspring Centering
1 - CLOCKSPRING ROTOR
2 - SCREW (2)
3 - HORN SWITCH CONNECTOR (2)
4 - AIRBAG CONNECTOR
8O - 14 RESTRAINTSVA
CLOCKSPRING (Continued)