Location, shown with code ZG3 (Engageable all-wheel drive with transmission ratio) |
1 | Transfer case |
2 | Selector drum |
3 | Worm gear |
4 | Torsion spring element |
B57 | Transfer case absolute sensor (turning angle sensor) |
M46/2 | Transfer case actuator motor |
D28.19-A005-82
Task
The transfer case actuator motor is used to turn the selector drum into the position specified by the all-wheel drive control unit (N45). On vehicles with code ZG1 (All-wheel drive, engageable), the all-wheel drive is switched on or off in this way. On all-wheel drive vehicles with code ZG3 (Engageable all-wheel drive with transmission ratio), the all-wheel drive and transmission ratio are switched on or off. The transfer case actuator motor is actuated by a pulse width modulated signal (PWM)).
Structure
The transfer case actuator motor consists of the following components:
Electric motor with worm gear for drive of selector drum
Torsion spring element for decoupling selector drums of electric motor with jammed gearshifts
Position sensor for recognition of turn rate and direction of rotation of transfer case actuator motor.
For end position recognition, the transfer case actuator motor is actuated by the all-wheel drive control unit with "circuit 15 ON". The actuator motor rotates the selector drum up to the end position and back again.