Top view of steering |
1 | Rack-and-pinion steering gear |
A91b1 | Electric power steering torque sensor |
A91m1 | Electric power steering actuator motor |
N68 | Electrical power steering control unit |
P46.20-2446-05
Location
The electrical power steering control unit is mounted onto the steering gear.
Tasks
The electrical power steering control unit has the following tasks:
Reading in of signals
Evaluation of input factors
Actuation of components
Transmission of requests/information
Reading in of signals
The input factors are read in via the following connections:
Direct line
Suspension FlexRay (Flex E)
Vehicle dynamics CAN (CAN H)
Direct line
The signals from the electric power steering torque sensor are read in over a direct line.
Chassis FlexRay
The following signals, among others, are read in via chassis FlexRay:
Steer Assist torque request and wheel speeds
Vehicle speed
Engine speed (except model 253.99)
"Drivetrain operational" signal
Steering wheel angle and steering angle rate of change
Requested toothed rack position
Vehicle dynamics CAN
The electrical power steering control unit also reads in the following signals from the Supplemental Restraint System control unit (N2/10) over the vehicle dynamics CAN:
Vehicle turn rate
Lateral acceleration
Longitudinal acceleration
Evaluation of input factors
The read in input factors are evaluated by the integrated microprocessor and the corresponding component parts are actuated and the requests or information issued.
Actuation of components
The electric power steering actuator motor is actuated over a direct line.
Transmission of requests/information
The following requests/information are also sent over the suspension FlexRay:
Request to display warning message to instrument cluster (A1)
Steering torque, steering angle rate of change and status of steering assistance to the Electronic Stability Program control unit (N30/4)
Current status from electrical power steering control unit