engine MERCEDES-BENZ ML320 1997 Complete Repair Manual

Fig. 103: Identifying Refrigerant Compressor Components
REFRIGERANT COMPRESSOR, LOCATION/TASK/DESIGN/FUNCTION - GF83.55-P-2100GH
ENGINES 111.977, 112.942, 113.942/981, 612.963 in MODEL 163 up to 31.08.01 with CODE (580) Air
conditioning or Tempmatic for USA refrigerant compressor 7SB16C
Design
Refrigerant compressor 7SB16C
Fig. 104: Identifying Refrigerant Compressor 7SB16C Components

REFRIGERANT COMPRESSOR, LOCATION/TASK/DESIGN/FUNCTION - GF83.55-P-2100P
ENGINE 111, 112, 113, 271, 272, 611, 612, 642, 646 in MODEL 203.0 /2 with CODE (580) Air
conditioning (or Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581)
Automatic air conditioning with CODE (581) Comfort automatic air conditioning
Refrigerant compressor,
position GF83.55-P-2100-
01GH
Refrigerant compressor,
taskThe refrigerant compressor (A9) is responsible for induction
and compression of the refrigerant.
Refrigerant compressor,
function GF83.55-P-2100-
02A

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 126 © 2006 Mitchell Repair Information Company, LLC.

ENGINE 111, 112, 271, 272, 611, 612, 646 in MODEL 203.7 with CODE (580) Air conditioning (or
Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581) Automatic air
conditioning with CODE (581) Comfort automatic air conditioning
ENGINE 112.942 /970, 113.942 /965 /981, 612.963, 628.963 in MODEL 163 as of 1.9.01 with CODE (580)
Automatic air conditioning
ENGINE 112, 113, 271, 272, 273, 612, 642, 646 in MODEL 209.3
ENGINE 112, 113, 271, 272, 273, 642 in MODEL 209.4
Shown on model 203
Fig. 105: Identifying Refrigerant Compressor
- Shown On Model 203
ELECTROMAGNETIC CLUTCH, FUNCTION - GF83.55-P-2101-01A
Electromagnetic clutch (A9k1)
Refrigerant compressor,
positionThe refrigerant compressor (A9) is flange-mounted to the
left front of the engine.
Model 163GF83.55-P-2100-
01GH
Refrigerant compressor,
taskThe refrigerant compressor (A9) is responsible for induction
and compression of the refrigerant.
Refrigerant compressor,
design GF83.55-P-2100-
03P
Refrigerant compressor,
function GF83.55-P-2100-
02P

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
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Fig. 106: Identifying Electromagnetic Clutch (A9K1) Components
Function
In order to start operating the refrigerant compressor, the push-button control module (N19, N22) actuates the
electromagnetic clutch (A9k1) and the solenoid (5) is supplied with electrical current. The magnetic force
attracts the pressure plate (6) against the rubber insert (7) and holds it securely. This creates the frictional
connection between the automotive engine and the refrigerant compressor. If the solenoid (5) is de-energized,
then the pressure plate (6) is pressed back by the rubber insert (7) into its rest position and the frictional
connection is interrupted.
Safety shutoff of the refrigerant compressor
To prevent a mechanical defect in the refrigerant compressor from causing the poly V-belt to jump loose, the
electromagnetic clutch releases itself automatically. With a mechanical defect, the refrigerant compressor
rotates more sluggishly or even locks completely. The heat generated at the friction surface causes the melting
fuse (2) in the solenoid (5) to melt. The current supply to the solenoid (5) is interrupted and the frictional
connection is released.
ELECTROMAGNETIC CLUTCH, LOCATION - GF83.55-P-2101-02GH
The electromagnetic clutch (A9k1) is located on the drive shaft of the refrigerant compressor (A9) at the front
left in the en
gine compartment.

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 128 © 2006 Mitchell Repair Information Company, LLC.

ELECTROMAGNETIC CLUTCH POSITION/TASK/DESIGN/FUNCTION - GF83.55-P-2101GH
ENGINES 111.977, 112.942, 113.942/981, 612.963 in MODEL 163 up to 31.08.01 with CODE (580) Air
conditioning or Tempmatic for USA
Electromagnetic clutch (A9k1)
Fig. 109: Identifying Electromagnetic Clutch (A9K1) Components

REFRIGERANT COMPRESSOR CONTROL VALVE, FUNCTION - GF83.55-P-2102-02P
Electromagnetic clutch,
location GF83.55-P-
2101-02GH
Electromagnetic clutch,
task
Switching the frictional connection between the
automotive engine and the refrigerant compressor
Switching off the refrigerant compressor with a
mechanical defect.

Electromagnetic clutch,
design GF83.55-P-
2101-03GH
Electromagnetic clutch,
function GF83.55-P-
2101-01A

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:16 PMPage 130 © 2006 Mitchell Repair Information Company, LLC.

Fig. 111: Identifying Refrigerant Compressor Control Valve, Function (2 Of 2)
Control at max. swept volume
(e.g. at higher ambient temperature or higher cooling capacity requirement)
If the suction pressure (Ps) rises above the diaphragm pressure (Ps1) in the refrigerant compressor control valve
and the control current is increased at the same time, in the refrigerant compressor control valve the passage -
high pressure (Pd) to crankcase pressure (Pc) - is closed by the control plunger (2). The crankcase pressure (Pc)
drops, as no refrigerant flows from the high pressure side into the crankcase via the refrigerant compressor
control valve.
In the long-term the bypass (1) sets up a pressure compensation between the suction pressure (Ps) and crankcase
pressure (Pc), i.e. the sum of the reaction forces on the left side, resulting from the crankcase pressure (Pc),
return force of the swash plate (centrifugal force) and the spring return force, is therefore smaller than the sum
of the piston forces. The swash plate angle extends to beyond the "0-position ", i.e. the inclined position
increases continuously to the swash plate's mechanical limit stop at the stop plate. The piston stroke increases
linear to the swash plate's inclination till it reaches max. volumetric flow.
CONTROL VALVE, LOCATION/TASK/FUNCTION - GF83.55-P-2102P
ENGINE 111, 112, 113, 271, 272, 611, 612, 642, 646 in MODEL 203.0 /2 with CODE (580) Air
conditioning (or Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581)
Automatic air conditioning with CODE (581) Comfort automatic air conditioning

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 132 © 2006 Mitchell Repair Information Company, LLC.

ENGINE 111, 112, 271, 272, 611, 612, 646 in MODEL 203.7 with CODE (580) Air conditioning (or
Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581) Automatic air
conditioning with CODE (581) Comfort automatic air conditioning
ENGINE 112.942 /970, 113.942 /965 /981, 612.963, 628.963 in MODEL 163 as of 1.9.01 with CODE (580)
Automatic air conditioning
ENGINE 112, 113, 271, 272, 273, 612, 642, 646 in MODEL 209.3
ENGINE 112, 113, 271, 272, 273, 642 in MODEL 209.4
Shown on model 203
Fig. 112: Identifying Refrigerant Compressor Control Valve And Compressor
- Shown On Model 203
BELT PULLEY, FUNCTION - GF83.55-P-2103-02P
Function under normal operating conditions
Under normal operating conditions the rubber (2) is deformation resistant. Thus it transmits the belt pulley's (3)
torque to the hub (1) and at the same time to the refrigerant compressor shaft, whereby the hub (1) and belt
pulley (3) turn in the direction of the arrow.
The refrigerant compressor torque < the rubber torque limit (2). In this operating condition, the rubber (2) acts
as a shock absorber b
y inhibiting resonance via the belt with other engine components.
Refrigerant compressor
control valve, positionThe refrigerant compressor control valve (1) is located on the
refrigerant compressor (A9).
Refrigerant compressor
control valve, taskThe refrigerant compressor control valve (1) regulates the swept
volume of the refrigerant compressor (A9) dependent upon the
refrigerant capacity requirement.

Refrigerant compressor
control valve, function GF83.55-P-
2102-02P

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 133 © 2006 Mitchell Repair Information Company, LLC.

Fig. 115: Identifying Belt Pulley, Design
BELT PULLEY, LOCATION/TASK/DESIGN/FUNCTION - GF83.55-P-2103P
ENGINE 111, 112, 113, 271, 272, 611, 612, 642, 646 in MODEL 203.0 /2 with CODE (580) Air
conditioning (or Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581)
Automatic air conditioning with CODE (581) Comfort automatic air conditioning
ENGINE 111, 112, 271, 272, 611, 612, 646 in MODEL 203.7 with CODE (580) Air conditioning (or
Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581) Automatic air
conditioning with CODE (581) Comfort automatic air conditioning
ENGINE 112.942 /970, 113.942 /965 /981, 612.963, 628.963 in MODEL 163 as of 1.9.01 with CODE (580)
Automatic air conditioning
ENGINE 112, 113, 271, 272, 273, 612, 642, 646 in MODEL 209.3
ENGINE 112, 113, 271, 272, 273, 642 in MODEL 209.4
Shown on model 203

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 135 © 2006 Mitchell Repair Information Company, LLC.

Fig. 116: Identifying Belt Pulley And Refrigerant Compressor - Shown On Model 203
PRESSURE RELIEF VALVE, FUNCTION - GF83.55-P-2104-02P
The pressure relief valve is a pressure sensitive wax valve. It is used when all other pressure-dependent safety
devices cannot prevent a pressure rise in the refrigerant compressor (A9).
The wax can withstand a pressure of approx. 35 bar. If the pressure increases to above this value, the wax fuse
is destroyed and pressure is released through the created opening.
PRESSURE RELIEF VALVE, LOCATION / TASK / FUNCTION - GF83.55-P-2104P
ENGINE 111, 112, 113, 271, 272, 611, 612, 642, 646 in MODEL 203.0 /2 with CODE (580) Air
conditioning (or Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581)
Automatic air conditioning with CODE (581) Comfort automatic air conditioning
ENGINE 111, 112, 271, 272, 611, 612, 646 in MODEL 203.7 with CODE (580) Air conditioning (or
Tempmatic for USA) with CODE (580) Automatic air conditioning with CODE (581) Automatic air
conditioning with CODE (581) Comfort automatic air conditioning
ENGINE 112.942 /970, 113.942 /965 /981, 612.963, 628.963 in MODEL 163 as of 1.9.01 with CODE (580)
Automatic air conditioning
ENGINE 112, 113, 271, 272, 273, 612, 642, 646 in MODEL 209.3
ENGINE 112, 113, 271, 272, 273, 642 in MODEL 209.4
Belt pulley,
positionThe belt pulley (2) is located on the front of the drive shaft on the
refrigerant compressor (A9).
Belt pulley,
taskThe belt pulley (2) drives the refrigerant compressor (A9). In addition
the pulley (2) is also used as a torque damper and a torque limiter.
Belt pulley,
design GF83.55-P-
2103-03P
Belt pulley,
function GF83.55-P-
2103-02P

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 136 © 2006 Mitchell Repair Information Company, LLC.

Shown on model 203
Fig. 117: Identifying Pressure Relief Valve And Refrigerant Compressor
- Shown On Model 203
TEMPERATURE CONTROL, FUNCTION - GF83.57-P-2000GH
MODEL 163 up to 31.08.01 with CODE (580) Air conditioning or Tempmatic for USA
Function
The temperature preselected at the temperature selector wheels is reached or kept constant by:
heating up by the heat exchanger,
heating up by the electric heater booster (with engine 612.963 only)
cooling by the evaporator core,
cooling and reheating (reheat mode).
Heating up
The heating system heat exchanger heats the air passing by, which is then conducted into the vehicle interior by
the air ducts.
Heating up by the electric heater booster
Due to the high level of efficiency of the direct-injection diesel engine, the heat output of the coolant is not
sufficient to heat the fresh air. By installing the electric heater booster, behind the heating system heat
exchanger, this heating capacity deficit is compensated.
Pressure relief
valve, positionThe pressure relief valve (3) is located on the refrigerant
compressor (A9).
Pressure relief
valve, taskThe pressure relief valve (3) serves to protect the refrigerant
circuit from damage caused by excess pressure.
Pressure relief
valve, function GF83.55-P-
2104-02P

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 137 © 2006 Mitchell Repair Information Company, LLC.

Cooling down
The thermostatic expansion valve located on the evaporator core serves to expand the liquid refrigerant which is
under high pressure thus lowering its pressure. After this the refrigerant evaporates. The evaporation heat
required for this is taken from the air flowing through the evaporator. The resulting cooled down air then
succeeds in entering the passenger compartment via the air ducts.
Reheat mode
The air which has been cooled down and dehumidified by the evaporator core is heated up again by the heat
exchanger (reheat). This serves to prevent the windows from misting up on the inside.
Temperature selector wheel, location/task/
design/function GF83.25-P-
2102GC
Heating system heat exchanger, location/
purpose/function GF83.20-P-
2108GC
Evaporator, location/purpose/design/function GF83.40-P-
2121GC
Expansion valve, location/task/design/function GF83.40-P-
2123GC
Refrigerant compressor, location/task/design/ function GF83.55-P-
2100GH
In-car temperature sensor, location/task/functionwith suction jet nozzle up to
30.11.99GF83.57-P-
2115GH
In-car temperature sensor with ventilation fan,
location/task/functionas of 01.12.99GF83.57-P-
2107GH
Defroster protection temperature sensor,
location/task/function GF83.57-P-
2113GH
Blending air flap actuator, location / task / function GF83.57-P-
2112GC
Outside temperature sensor, location/task/ functionas of 01.12.99GF83.57-P-
2110GH
Air conditioning control module, location/task/ function GF83.30-P-
2102GH
All Activity Module, location/task/function GF54.21-P-
4110GH
Electric heater booster position/task/design/ function Engine 612.963GF83.70-P-
4054GH
Temperature regulator microswitch, location/
task/function Engine 612.963GF83.70-P-
4055GH
Extended activity module, position/task GF54.21-P-
4106GH
Extended Activity Module, location/task/designas of 1.12.99GF54.21-P-
4107GK

2001 Mercedes-Benz ML320
1998-2005 HVAC Climate Control - 163 Chassis
me
Saturday, October 02, 2010 3:23:17 PMPage 138 © 2006 Mitchell Repair Information Company, LLC.