Power Steering Control System: Overview Nissan Rogue I рестайлинг

System Description

1. EPS control unit performs an arithmetical operation on data, such as steering wheel turning force (sensor signal) from the torque sensor, vehicle speed signal, etc. Then it generates an optimum assist torque signal to the EPS motor according to the driving condition.
2. EPS control unit decreases the output signal to EPS motor while extremely using the power steering function (e.g., full steering) consecutively for protecting EPS motor and EPS control unit (Overload protection control). While activating overload protection control, the assist torque gradually decreases, and the steering wheel turning force becomes heavy. The normal assist torque reactivates by no steering.
3. In case of an error in the electrical system, the fail-safe function stops output signals to the EPS motor. Then the previous state is changed to the manual steering state.
4. Self-diagnosis can be done with CONSULT-III.
5. EPS control unit will decrease assistance under the following 2 conditions. Extensive steering at low speed will cause the ECU and MOTOR to heat up, once temperature reaches critical point ECU will reduce current to reduce heat up. System will recover as temperature lowers (reduced or no assistance). Holding steering on rack-end (full lock) for 1 second will cause the system to engage rack-end protection. This reduces assistance down to 50% in order to prevent heat up. Assistance is immediately returned to 100% when steering released or turned away from rack-end.

Scheme 1

Component Description

EPS SYSTEM COMPONENTS REFERENCE CHART

Description

Power is supplied from the battery to EPS control unit.

Torque sensor detects the steering torque, and transmit the signal to EPS control unit.

EPS motor provides the assist torque by the control signal from EPS control unit.

EPS control unit incorporates a memory function.

EPS control unit performs an arithmetical operation on data, such as steering wheel turning force (sensor signal) from the torque sensor, vehicle speed signal, etc. Then it generates an optimum assist torque signal to the EPS motor according to the driving condition.

EPS control unit receives the vehicle speed signal from ABS actuator and electric unit (control unit) via CAN communication line.

EPS control unit receives the vehicle speed signal from combination meter via CAN communication line.

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Many electronic control units are equipped onto a vehicle, and each control unit shares information and links with other control units during operation (not independent). In CAN communication, control units are connected with 2 communication lines (CAN-H line, CAN-L line) allowing a high rate of information transmission with less wiring. Each control unit transmits/receives data but selectively reads required data only.

1. EPS warning lamp does not turn ON when turning ignition switch ON from OFF.

1. EPS warning lamp does not turn OFF several seconds after engine started.

OPERATION PROCEDURE

1. Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
2. Turn the ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock will remain released with both battery cables disconnected and the steering wheel can be turned.
4. Perform the necessary repair operation.
5. When the repair work is completed, re-connect both battery cables. With the brake pedal released, turn the ignition switch from ACC position to ON position, then to LOCK position. (The steering wheel will lock when the ignition switch is turned to LOCK position.)
6. Perform self-diagnosis check of all control units using CONSULT-III.

1. Connect both battery cables. NOTE: Supply power using jumper cables if battery is discharged.
2. Turn the ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock will remain released with both battery cables disconnected and the steering wheel can be turned.
4. Perform the necessary repair operation.
5. When the repair work is completed, re-connect both battery cables. With the brake pedal released, turn the ignition switch from ACC position to ON position, then to LOCK position. (The steering wheel will lock when the ignition switch is turned to LOCK position.)
6. Perform self-diagnosis check of all control units using CONSULT-III.

See also:
• CONSULT-III FUNCTION
• CONSULT-III FUNCTION
• CONSULT-III FUNCTION