Solenoid Valve - Mercedes-Benz 2005 Sprinter Service Manual

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VA

SOLENOID VALVE

DESCRIPTION
The rear A/C solenoid valve is a two-position elec-
trically operated shut-off valve, which is used to con-
trol refrigerant flow to the rear A/C evaporator from
the A/C compressor. The solenoid valve is located in
the rear A/C evaporator housing and is attached by a
bracket.
OPERATION
The solenoid valve is used by the rear A/C control
module to control rear A/C output temperature and
to prevent evaporator freezing. Evaporator tempera-
ture is controlled by cycling the solenoid valve open
and closed, thereby controlling refrigerant flow to the
rear evaporator. The normally closed valve only
allows refrigerant to flow through it when power is
supplied to the solenoid by the rear A/C control mod-
ule.
DIAGNOSIS AND TESTING
For circuit descriptions and diagrams, refer to Air
Conditioning/Heater in Group 8W - Wiring Diagrams.
NOTE: Prior to performing the following checks,
verify that the front A/C system is operating prop-
erly.
(1) With the engine running, the front A/C switch
in the On position and the rear A/C blower switch in
the Off position, check that the rear evaporator is not
colder than the ambient temperature. If the evapora-
tor temperature is colder than the ambient tempera-
ture, the solenoid is allowing refrigerant to flow
through the rear evaporator when in the closed posi-
tion. If OK, go to Step 2. If not OK, replace the rear
A/C solenoid valve (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/SOLENOID - REMOV-
AL).
(2) With the ignition switch in the Off position and
the rear A/C solenoid valve wire harness discon-
nected, check for continuity between the two solenoid
valve terminals. If OK, go to Step 3. If not OK,
replace the solenoid valve (Refer to 24 - HEATING &
AIR
CONDITIONING/CONTROLS/SOLENOID
REMOVAL).
(3) With the ignition switch in the Off position and
the rear A/C solenoid valve wire harness discon-
nected, check the solenoid valve ground circuits for a
good ground at all times. If OK, go to Step 4. If not
OK, repair the open circuit to ground as required.
(4) With the ignition switch and the front A/C
switch in the On position and the rear A/C solenoid
valve wire harness disconnected, check the harness
for battery power at terminal 2. If OK, replace the
solenoid valve (Refer to 24 - HEATING & AIR CON-
DITIONING/CONTROLS/SOLENOID - REMOVAL).
If not OK, test the A/C control module as required
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS/POWER MODULE - DIAGNOSIS AND
TESTING).
REMOVAL
(1) Recover the refrigerant from the refrigerant
system (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE).
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the rear dome light from the rear roof
duct panel (Fig. 7).
(4) Disconnect the dome light wire harness connec-
tor and remove the dome light from vehicle.
(5) Remove the six push-pin roof duct panel fasten-
ers and remove the duct panel from the vehicle.
(6) Remove the five evaporator panel screws at the
front of the panel.
Fig. 7 Rear Roof Duct Panel
-
1 - SCREW (5)
2 - PUSH-PIN FASTENER (6)
3 - REAR DOME LAMP
4 - ROOF DUCT PANEL
(7) If equipped, remove the interior motion sensor
from the evaporator panel, disconnect the wire har-
ness connector and remove the motion sensor from
the vehicle (Fig. 8).
(8) Remove the three push-in evaporator panel fas-
teners at the rear of the panel.
CONTROLS - REAR 24 - 27

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