Electrical power steering control unit (ES), component description

P46.35-2077-06

A91b1 Electric power steering torque sensor

A91m1 Electric power steering actuator motor

N68 Electrical power steering control unit

Location

The electrical power steering control unit is installed on the electric power steering actuator motor.

Task

The electrical power steering control unit has the following tasks:

 Reading in of sensors and signals

 Evaluation of input factors

 Actuation of components

 Transmission of requests/information

Reading in of sensors and signals

The input factors are read in via the following connections:

 Direct line

 Chassis CAN 2 (CAN E2)

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Direct line

The following sensor is read in via a direct line:

- Electric power steering torque sensor

Chassis CAN 2 (signal flow over chassis CAN 1 to chassis CAN 2 with front SAM control unit with fuse and relay module interface (N10/1))

The following signals are read in over chassis CAN 2:

- Steering assistance torque request and wheel speed, from Electronic Stability Program control unit (N30/4)

- "Engine running" status, "drivetrain ready" and engine rpm, from ME-SFI [ME] control unit (N3/10)

- Steering wheel angle (recorded by steering wheel angle sensor (N49)) and steering angle speed, from steering column tube module control unit (N80)

- Current status and requested toothed rack position of parking system control unit (N62) (with code (220) PARKTRONIC or with code (235) Active Parking Assist)

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Evaluation of input factors

The input factors which are read in are evaluated by the integrated microprocessor, the relevant components are then actuated and requests/information are output.

Actuation of components

The following component is actuated directly:

- Electric power steering actuator motor

Transmission of requests/information

The following requests/information are sent over the chassis CAN 1 and chassis CAN 2 with the front SAM control unit with fuse and relay module interface:

- Request for warning message in multifunction display (A1p13) of instrument cluster (A1)

- Steering torque, steering angle speed and status of steering assistance to Electronic Stability Program control unit

- Current status from electrical power steering control unit

- Current toothed rack position