Mercedes C-Class

W203 since 2000 of release

Repair and operation of the car



Mercedes-Benz
+ Mercedes-Benz cars of class C (W-203)
+ Operation manual
+ Routine maintenance
+ Engine
+ Cooling system and heating
+ Power supply system and release
+ Engine electric equipment
+ Manual transmission
- Automatic transmission
   Specifications
   - The automated box of gear shifting 716.6
      Elements of hydraulic management automated by the Sequentronic check point
      Elements of electronic control and signals of the control unit automated by the Sequentronic check point
   + Automatic transmission 722.6
+ Coupling and power shafts
+ Brake system
+ Suspension bracket and steering
+ Body
+ Onboard electric equipment







The automated box of gear shifting 716.6

Elements of hydraulic management automated by the Sequentronic check point

Hinged elements automated by the Sequentronic check point

1 — a ventilation Cover
2 — the ventilation Valve
3 — the Accumulator
4 — the coupling switching off Lever
5 — the Sealing cap
6 — the Forward case of the check point
7 — the Switch of recognition of transfers
8 — the speed Sensor
9 — the Holder of the sensor of recognition of transfers
10 — a check point Case
11 — the Pump
12 — the Tank
13 — the Hydraulic block

Elements of a hydraulic actuator of management of coupling and switching automated by the Sequentronic check point


The hydraulic control unit automated by the check point (Sequentronic)

2 — Valvate assembly
2a — the Socket of the pressure head line
2b — the Socket of the returnable line
2s — the Oil filter
2d — the Socket of the pressure head line of switching off of coupling
3 — the Executive cylinder
Y90 — the Electromagnetic valve of coupling of system of automatic gear shifting
Y91 — the Electromagnetic valve of braking automated by the check point with the built-in reducing valve
Y92/1 — the Electromagnetic valve of switchings 1, 3, 5
Y92/2 — the Electromagnetic valve of switchings R, 2, 4, 6

The hydraulic pump automated by the Sequentronic check point

4 — the Electric motor
4a — the Gear pump
4b — the Maslozaborny socket
4s — the Socket of the pressure head line
M46 — the Hydraulic pump Sequentronic [ASG]

Sequentronic coupling hydraulic actuator

13a — the Casing
13b — the Persistent ring
13s — Balls
13d — the Protective cover
13e — Pruzhina of preliminary loading
13f — the Sealant
13g — the Working piston
13h — the Coupling
And — the Provision of the switched-off coupling
In — Basic situation. Coupling is included
B53 — the coupling course Sensor

Functioning of a hydraulic actuator of coupling

0 — the Channel of return of liquid
A — the Central hydraulic release device of coupling
A1 — Pruzhina
A2 — the Working piston
B — Valvate assembly
I \Pressure chamber of I
p — Hydraulic pressure
Y90 — the Electromagnetic valve of coupling

Principle of functioning of the hydraulic control unit

Supply of oil to electromagnetic valves

The oil (Pentosin) forced by the hydraulic pump on the steel line moves in valvate assembly (2), is pumped over through an oil filter (2s) and via the control valve arrives to electromagnetic valves of coupling (Y90), switchings (Y92/1 and Y92/2) and braking (Y91)

Management of coupling

Activation of the electromagnetic valve of coupling (Y90) is carried out on command from the control unit of transmission (N15/6) and provides supply of oil on the pressure head line connected to the socket of the coupling drive, (2D) in executive knot.

Management of gear shifting

Depending on the current traffic conditions the control unit (N15/6) makes activation of the corresponding electromagnetic valve of switching (Y92/1 or Y92/2) of valvate assembly. The activated valve provides giving of hydraulic pressure in the switching cylinder influencing the central rod of switching and providing the choice of the required transfer by means of the corresponding connecting elements to transmissions.

Principle of functioning of the hydraulic pump

The electric motor (4) is activated at the command of the control unit (N15/6) and provides the drive of the gear pump connected to the coupling (4a).

Rotation of gear wheels provides absorption of working liquid (oil) via the inlet socket (4b), its compression and giving under pressure via the socket (4s).

The pump also provides pumping of oil in a receiver of system pressure.

Principle of functioning of a hydraulic actuator of coupling

The working piston (13g) under the pressure of hydraulic pressure is displaced forward in the coupling (13h). The persistent ring (13b) wrings out a disk spring and activates coupling.

Internal sealing is provided at the expense of a sealant (13f).

The protective cover (13d) provides protection of a moving surface of the release device of coupling against dirt hit. The preloading spring (13e) provides minimization of initial loading of the drive of the release bearing for the purpose of decrease in level of a noise background.

At the switched-off coupling

The control unit (N15/6) activates the electromagnetic valve (Y90) in valvate assembly (V) which provides giving of hydraulic pressure (r) in the release device(s). The working piston (A2) is displaced forward, towards a disk spring. The persistent ring nestles on a disk spring, providing its dehiscence.

At the included coupling

The valve (Y90) in valvate assembly (V) is not activated and the returnable spring holds it in basic situation. As a result the pressure chamber of I in the hydraulic release device(s) turns out unloaded what guarantees existence of communication with final port of the oil tank (0).