radio controls MERCEDES-BENZ SPRINTER 2005 Service Repair Manual

(11) Reconnect the engine wire harness connector
for the compressor clutch coil to the coil wire harness
connector on the top of the compressor.
(12) Reinstall the serpentine accessory drive belt
(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - INSTALLATION).
(13) Reconnect the battery negative cable.
(14) If a new clutch plate and/or clutch pulley are
being installed, the new clutch components must be
burnished (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS/A/C COMPRESSOR CLUTCH
- STANDARD PROCEDURE).
A/C COMPRESSOR CLUTCH
COIL
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL
The air conditioning compressor clutch coil electri-
cal circuit is controlled by the ATC control module
which is integral to the heater-A/C control. Begin
testing of a suspected compressor clutch coil problem
by performing the ATC Function Test using the
DRBIIItscan tool.
A/C HEATER CONTROL
DESCRIPTION
This ATC system uses a combination of electrical
and mechanical controls. These controls provide the
vehicle operator with a number of setting options to
help control the climate and comfort within the vehi-
cle.
The A/C-heater control panel is located on the
instrument panel inboard of the steering column and
below the radio (Fig. 7). The A/C-heater control panel
contains a rotary-type temperature control knob, a
rotary-type mode control knob, a thumbwheel-type
blower motor speed control and an air conditioning
compressor push button switch and indicator lamp.
The A/C-heater control panel also features a push
button switch and indicator lamp for the residual
engine heat utilization (REST) function, cabin heater
or the heater booster (as equipped).
The A/C-heater control panel cannot be adjusted or
repaired and, if faulty or damaged, it must be
replaced.
OPERATION
To control the interior temperature, the A/C-heater
control module uses the actual values from the tem-
perature sensors and the CAN bus and compares
them with the nominal value of the temperature con-
trol switch.The A/C-heater control panel is serviced only as
complete unit and cannot be repaired. If faulty or
damaged, the entire control panel unit must be
replaced.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL).
(3) Remove the two screws that secure the A/C-
heater control to the instrument panel (Fig. 8).
(4) Pull the A/C-heater control away from the
instrument panel far enough to access the connec-
tions on the back of the control.
(5) Mark and disconnect the two control cables
from the A/C-heater control.
Fig. 7 A/C-Heater Control Panel
24 - 12 CONTROLS - FRONTVA
A/C COMPRESSOR CLUTCH (Continued)

OPERATION
The evaporator temperature sensor monitors the
temperature of the evaporator. The sensor will
change its internal resistance in response to the tem-
peratures it monitors. The ATC control module is
connected to the sensor through a sensor ground cir-
cuit and a sensor signal circuit. As the evaporator
temperature increases, the resistance of the sensor
decreases and the voltage monitored by the module
decreases. The module uses this monitored voltage
reading to an indication of the evaporator tempera-
ture. The ATC control module is programmed to
respond to this input by cycling the air conditioning
compressor clutch as necessary to optimize air condi-
tioning system performance and to protect the sys-
tem from evaporator freezing. The external location
of the sensor allows the sensor to be removed or
installed without disturbing the refrigerant in the
system. The evaporator temperature sensor is diag-
nosed by performing the ATC Function Test using a
DRBIIItscan tool. Refer to Body Diagnostic Proce-
dures.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the radio (Refer to 8 - ELECTRICAL/
AUDIO/RADIO - REMOVAL).
(3) Remove glove compartment.
(4) Remove cover from instrument cluster (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - REMOVAL).
(5) Remove the instrument cluster (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - REMOV-
AL).
(6) Remove passenger side airbag.
(7) Remove cover above air nozzle on passenger
side.
(8) Remove speaker.
(9) Remove center section of instrument panel.
(10) Remove heater-A/C control from the instru-
ment panel (Refer to 24 - HEATING & AIR CONDI-
TIONING/CONTROLS/A/C HEATER CONTROL -
REMOVAL).
(11) Remove instrument panel top section.
(12) Remove electrical connections.
(13) Remove air bezels from instrument panel.
(14) Disconnect the wire harness connector from
evaporator temperature sensor (Fig. 13).
(15) Remove evaporator temperature sensor from
heater housing.
INSTALLATION
(1) Install the new probe into the evaporator.
NOTE: The new probe must not go into the same
hole (in the evaporator core) that the old probe was
removed from.
(2) Install the wire harness connector to the evap-
orator temperature sensor.
(3) Install the air bezels to the instrument panel.
(4) Install the electrical connections.
(5) Install the instrument panel top section (Refer
to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - INSTALLATION).
(6) Install the heater-A/C control (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - INSTALLATION).
(7) Install the center section of the instrument
panel.
(8) Install the speaker (Refer to 8 - ELECTRICAL/
AUDIO/SPEAKER - INSTALLATION).
(9) Install the cover above the air nozzle on the
passenger side.
(10) Install the passenger side airbag.
(11) Install the instrument cluster (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - INSTAL-
LATION).
Fig. 13 Evaporator Temperature Sensor
1 - WIRE HARNESS CONNECTOR
2 - EVAPORATOR TEMPERATURE SENSOR
24 - 18 CONTROLS - FRONTVA
EVAPORATOR TEMPERATURE SENSOR (Continued)

(12) Install the cover to the instrument cluster.
(13) Install glove compartment.
(14) Install the radio (Refer to 8 - ELECTRICAL/
AUDIO/RADIO - INSTALLATION).
(15) Reconnect the battery negative cable.
IN-CAR TEMPERATURE
SENSOR
DESCRIPTION
The in-car temperature sensor measures the actual
air temperature within the passenger compartment.
The in-car temperature sensor is located inside of the
A/C-heater control behind a vented panel (Fig. 14)
and is not a separate serviceable component. The
A/C-heater control must be replaced if there is a fault
relating to the in-car temperature sensor.
OPERATION
Air from the passenger compartment flows over the
thermistor of the in-car temperature sensor. The
thermistor changes resistance with air temperature.
The ATC control module measures this resistance
and calculates the temperature of the air. The ATC
control module then makes adjustments to maintain
the selected passenger compartment temperature.
DIAGNOSIS AND TESTING
The in-car temperature sensor is diagnosed by per-
forming the ATC Function Test using the DRBIIIt
scan tool. Refer to Body Diagnostic Procedures. For
circuit descriptions and diagrams, refer to the appro-
priate wiring information.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
If the in-car temperature sensor is verified to be
bad, the A/C-heater control must be replaced (Refer
to 24 - HEATING & AIR CONDITIONING/CON-
TROLS/A/C HEATER CONTROL - REMOVAL).
MODE DOOR CABLES
REMOVAL
The air distribution control cables (mode door
cables) can be removed and installed without having
to remove the instrument panel from the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the center section of the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL).
(3) Remove the heater-A/C control (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL).
(4) Mark and disconnect the control cables from
the A/C-heater control.
(5) Mark and disconnect the control cables from
the heater housing retainers (Fig. 15).
(6) Disconnect the control cables from the mode
door levers and remove the cables from the vehicle.
INSTALLATION
(1) Connect the two control cables to the mode
door levers (Fig. 16).
(2) Connect the two control cables to the A/C-
heater control.
NOTE: Install the control cable of bottom adjust-
ment lever to the front adjustment wheel of the A/C-
heater control.
(3) Hold the A/C-heater control in its installation
position.
Fig. 14 In-Car Temperature Sensor
1 - A/C-HEATER CONTROL
2 - IN-CAR TEMPERATURE SENSOR
VACONTROLS - FRONT 24 - 19
EVAPORATOR TEMPERATURE SENSOR (Continued)