Automatic Transmission/Transaxle: Description and Operation

Brief Description

The 6 forward gears and the reverse gear are generated by a double planetary gear set (Ravigneaux) and a front-mounted simple planetary gear.
The way these planetary gear-sets work together, is patented (Lepelletier).

Also new: The stationary disconnect feature, what means that the gearbox is disconnected from the power train at standstill (clutch A is open).
This causes an additional reduction of fuel consumption.
Former the torque converter ran against the motor (foot on the brake) at standstill.

The 6HP26 uses the new "ASIS" shift strategy developed by ZF (Adaptive Shift Strategy).










Operating Elements





*MV1 : EDS4 Switching function (OFF: Clutch-E, ON: Brake-D)
*LC : Lock-up clutch

Mechatronic

Mechatronic consists of the hydraulic valve body assembly and the TCU module.
There are the TCU, two speed sensors, position sensor(inhibitor switch), oil temperature sensor on the E-module.
Position sensor





Key to sensor coding:
Logical 0 means transistor block, electric high
Logical 1 means transistor pass, electric low
X means this wire is needed
Z means intermediate position

Task of position sensor
Conversion of linear shift valve or parking lock movement into a parallel coded signal on 4 wires (L1, L2, L3, L4) in accordance with the positions P, R, N, D, 4, 3, 2 and P_on and P_off (parking lock engaged/disengaged)

The two speed sensors for turbine and output speeds and the oil temperature sensor and position switch are integrated into the TCU module and are not detachable.
The solenoid valves and pressure regulators are attached by the knife-edge clamping technique.