Page 1857 of 2305

Torque Converter Lockup Clutch Regulating Valve
The torque converter lockup clutch regulating
valve (6) (Fig. 113) regulates the torque converter
lock-up clutch working pressure (p-TCC) in relation
to the torque converter clutch control pressure (p-S/
TCC). According to the size of the working pressure
(p-A), the torque converter lockup clutch is either
Engaged, Disengaged, or Slipping. When the regulat-
ing valve (6) is in the lower position, lubricating oil
flows through the torque converter and oil cooler (8)
into the transmission (torque converter lockup clutch
unpressurized). In its regulating position (slipping,
torque converter lockup clutch pressurized), a
reduced volume of lubricating oil flows through the
annular passage (7) bypassing the torque converter
and passing direct through the oil cooler into the
transmission. The rest of the lubricating oil is
directed via the throttle ªaº into the torque converter
in order to cool the torque converter lockup clutch.
Fig. 113 Torque Converter Lockup Clutch Regulating Valve
1 - TORQUE CONVERTER LOCK-UP CLUTCH
2 - TORQUE CONVERTER OUTPUT
3 - TORQUE CONVERTER INPUT
4 - LUBRICATION
5 - TORQUE CONVERTER LOCK-UP SOLENOID6 - TORQUE CONVERTER LOCK-UP CLUTCH REGULATING
VA LV E
7 - OIL COOLER
8 - LINE PRESSURE REGULATING VALVE
9 - OIL PUMP
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Page 1858 of 2305
Overlap Regulating Valve
During the shift phase the pressure (Fig. 114) in
the deactivating shift actuator is regulated in rela-
tion to the engine load (modulating pressure, p-Mod)
and the pressure in the activating actuator. The reg-
ulated pressure is inversely proportional to the trans-
fer capacity of the activating shift actuator (regulated
overlap).
Fig. 114 Overlap Regulating Valve
1 - OVERLAP REGULATING VALVE
2 - ANNULAR SURFACE ON OVERLAP REGULATING VALVE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 115
Page 1859 of 2305
Command Valve
When the end face is unpressurized (stationary
phase), the working pressure (p-A) is directed to the
actuated shift element. If the end face of the com-
mand valve (Fig. 115) is subjected to the shift valve
pressure (p-SV) (shift phase), then the shift pressure
(p-S) is switched to the activating element and the
overlap pressure (p-š) is switched to the deactivating
element.
Fig. 115 Command Valve
1 - HOLDING CLUTCH B1
2 - DRIVING CLUTCH K13 - 1-2/4-5 COMMAND VALVE
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Page 1860 of 2305
Shift Valve Holding Pressure
The holding pressure shift valve (1) (Fig. 116) is
actuated by the pressures present at the end face in
the actuators and a spring. It assigns the working
pressure (p-A) to the actuator with the higher pres-
sure (taking into account the spring force and the
effective surface area). The other element of the shift
group is then unpressurized. The valve switches over
only during the shift phase and only at a certain
pressure ratio between the overlap pressure (p-š)
and the shift pressure (p-S).
Fig. 116 Shift Valve Holding Pressure
1 - HOLDING PRESSURE SHIFT VALVE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 117
Page 1861 of 2305

Shift Pressure Shift Valve
When the multiple-disc brake B1 (3) is activated,
the working pressure (p-A) is applied to the end face
of the 1-2 / 4-5 shift pressure shift valve (4) (Fig. 117)
via the command valve (1). Its shift state is main-
tained during the shift phase by substituting the
shift element pressure acting on its end face (and
which is variable during the shift phase) with a cor-
responding constant pressure. When the multi-plate
clutch K1 (2) is activated, the end face of the shift
valve is unpressurized during the stationary and
shift phases, so the shift state is maintained during
the shift phase in this case too.Lubrication Pressure Regulating Valve
At the working pressure regulating valve surplus
oil is diverted to the lubrication pressure regulating
valve (1) (Fig. 118), from where the lubrication pres-
sure (p-Sm) is used in regulated amounts to supply
the transmission lubrication system including the
torque converter.
Fig. 117 Shift Pressure Shift Valve
1 - 1-2/4-5 COMMAND VALVE
2 - DRIVING CLUTCH K13 - HOLDING CLUTCH B1
4 - 1-2/4-5 SHIFT PRESSURE SHIFT VALVE
Fig. 118 Lubrication Pressure Regulating Valve
1 - LUBRICATION PRESSURE REGULATING VALVE
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Page 1862 of 2305

Shift Pressure Regulating Valve
The shift pressure is determined by the shift pres-
sure regulating solenoid valve and the shift pressure
regulating valve (3) (Fig. 119). In addition, pressure
from the clutch K2 (1) is also present at the annular
surface (2) of the shift pressure regulating valve (3).
This reduces the shift pressure in 2nd gear.
Regulating Valve Pressure Regulating Valve
The regulating valve pressure (p-RV) is set at the
regulating valve pressure regulating valve (1) (Fig.
120) in relation to the working pressure (p-A) as far
as the maximum pressure.Shift Valve Pressure Regulating Valve
The non-constant regulating valve pressure (p-RV)
is regulated to a constant shift valve pressure (p-SV)
at the shift valve pressure regulating valve (1) (Fig.
121) and is used to supply the 1-2 and 4-5 / 3-4 / 2-3
solenoid valves and the torque converter lockup
clutch PWM solenoid valve.
Fig. 119 Shift Pressure Regulating Valve
1 - SHIFT PRESSURE REGULATING VALVE
Fig. 120 Regulating Valve Pressure Regulating
Valve
1 - REGULATING VALVE PRESSURE REGULATING VALVE
Fig. 121 Shift Valve Pressure Regulating Valve
1 - SHIFT VALVE PRESSURE REGULATING VALVE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 119
Page 1863 of 2305
REMOVAL
(1) Drain transmission oil by unscrewing oil drain
plug (8) (Fig. 122).
NOTE: If the transmission fluid is burnt or contains
abraded particles, the oil cooler lines and oil cooler
must be flushed out.(2) Move selector lever to position ªPº.
(3) Raise vehicle.
(4) Remove bolt (3) (Fig. 123) and screw (1) hold-
ing the heat shield (2) to the transmission.
(5) Disconnect 13-pin plug connector (1) (Fig. 124).
Turn bayonet lock of guide bushing (2) anti-clock-
wise.
(6) Loosen guide bushing (2) and remove from
transmission housing.
Fig. 122 Remove Electrohydraulic Unit
1 - HEAT SHIELD
2 - ELECTROHYDRAULIC UNIT
3 - BOLT
4 - OIL FILTER
5 - OIL PAN
6 - CLAMPING ELEMENT
7 - BOLT
8 - DRAIN PLUG
9 - DRAIN PLUG GASKET
10 - 13-PIN PLUG CONNECTOR
11 - BOLT
12 - GUIDE BUSHING
Fig. 123 Remove Heat Shield
1 - SCREW
2 - HEAT SHIELD
3 - BOLT
Fig. 124 Remove Wiring Connector Plug
1 - PLUG CONNECTOR
2 - GUIDE BUSHING
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(7) Detach oil pan (5) (Fig. 125).
(8) Remove oil filter (4).
(9) Unscrew Torx socket bolts (3) and remove elec-
trohydraulic control module (2).
DISASSEMBLY
(1) Remove electrohydraulic unit from the vehicle.
(Refer to 21 - TRANSMISSION/AUTOMATIC
TRANSMISSION - NAG1/ELECTROHYDRAULIC
UNIT - REMOVAL)
(2) Remove solenoid caps (1, 2) (Fig. 126).
(3) Unscrew Torxtsocket bolts (3, 4) (Fig. 126).
NOTE: Pay attention to the different lengths of the
TorxTsocket bolts.
(4) Remove leaf springs (5).
(5) Withdraw solenoid valves (6 - 11) from shift
plate (13).
NOTE: Check O-rings on solenoid valves for dam-
age and replace if necessary.
(6) Bend away retaining lug on stiffening rib on
transmission oil temperature sensor.
(7) Remove electrohydraulic control module (12)
from the shift plate (13).
Fig. 125 Remove Electrohydraulic Unit
1 - HEAT SHIELD
2 - ELECTROHYDRAULIC UNIT
3 - BOLT
4 - OIL FILTER
5 - OIL PAN
6 - CLAMPING ELEMENT
7 - BOLT
8 - DRAIN PLUG
9 - DRAIN PLUG GASKET
10 - 13-PIN PLUG CONNECTOR
11 - BOLT
12 - GUIDE BUSHINGFig. 126 Electrical Unit Components
1 - SOLENOID CAP
2 - SOLENOID CAP
3 - BOLT - M6X32
4 - BOLT - M6X30
5 - LEAF SPRING
6 - MODULATING PRESSURE REGULATING SOLENOID VALVE
7 - SHIFT PRESSURE REGULATING SOLENOID
8 - 3-4 SHIFT SOLENOID
9 - TORQUE CONVERTER LOCK-UP SOLENOID
10 - 1-2/4-5 SHIFT SOLENOID
11 - 2-3 SHIFT SOLENOID
12 - ELECTRICHYDRAULIC CONTROL MODULE
13 - SHIFT PLATE
VAAUTOMATIC TRANSMISSION NAG1 - SERVICE INFORMATION 21 - 121