Nissan Versa

 Sedan Service Manual

Steering » Steering control system (STC)
Steering wheel turning force is heavy or light

Description

Steering wheel turning force is heavy or light.

Diagnosis Procedure

1.PERFORM SELF-DIAGNOSIS

With CONSULT

1. Turn the ignition switch OFF to ON.
2. Perform "EPS" self-diagnosis.

Is any DTC detected?

YES >> Check the DTC. Refer to STC "DTC Index".

NO >> GO TO 2.

2.CHECK THE ILLUMINATION OF THE EPS WARNING LAMP

Check that the EPS warning lamp turns ON when ignition switch turns ON. Then, EPS warning lamp turns OFF after the engine is started.

Is the inspection result normal?

YES >> GO TO 3.

NO >> Perform trouble diagnosis of EPS warning lamp. Refer to STC "Diagnosis Procedure".

3.CHECK EPS CONTROL UNIT SIGNAL (1)

With CONSULT

1. Start the engine.
2. Select "ASSIST LEVEL" in "DATA MONITOR" in "EPS".

Does the item in "DATA MONITOR" indicate "100%"?

YES >> GO TO 6.

NO >> GO TO 4.

4.CHECK EPS CONTROL UNIT SIGNAL (2)

With CONSULT

Select "BATTERY VOLT" in "DATA MONITOR" in "EPS".

Does the item in "DATA MONITOR" indicate "10 V" or more?

YES >> GO TO 5.

NO >> Perform trouble diagnosis of EPS control unit power supply and ground. Refer to STC"Diagnosis Procedure".

5.CHECK EPS CONTROL UNIT SIGNAL (3)

With CONSULT

1. Select "ASSIST LEVEL" in "DATA MONITOR" in "EPS".
2. Stop the EPS system until the item in "DATA MONITOR" becomes "100%".

   NOTE: While stopping the EPS system, do not turn steering wheel.

3. Check that the symptom continues.

Does the symptom continue?

YES >> GO TO 6.

NO >> The assist torque decreases because of protection function. This is not a malfunction. Inspection End.

6.CHECK EPS CONTROL UNIT SIGNAL (4)

With CONSULT

1. Start the engine.

   CAUTION: Never drive the vehicle.

2. Turn steering wheel from full left stop to full right stop.
3. Select "TORQUE SENSOR" in "DATA MONITOR" in "EPS".   

Is the inspection result normal?

YES >> GO TO 8.

NO >> GO TO 7.

7.CHECK EPS MOTOR

Perform the trouble diagnosis of EPS motor. Refer to STC "Diagnosis Procedure".

Is the inspection result normal?

YES >> GO TO 8.

NO >> Repair or replace the malfunctioning component.

8.CHECK STEERING WHEEL TURNING FORCE

Check the steering wheel turning force. Refer to ST"Inspection".

Is the inspection result normal?

YES >> Inspection End

NO >> Check the steering wheel turning force for mechanical malfunction. Refer to ST "Inspection".

Precautions

EPS System

Diagnosis system (EPS control unit)

EPS control unit

Diagnosis and repair workflow

C1601 Battery power supply

C1604 Torque sensor

C1606 EPS Motor

C1607, C1608 EPS Control unit

C1609 Vehicle speed signal

C1610 Engine status signal

U1000 CAN Comm circuit

EPS Warning lamp

EPS Warning lamp does not turn OFF

Steering wheel turning force is heavy or light

Unbalance steering wheel turning force and return between right and left

Unbalance steering wheel turning force (torque variation)

EPS Control unit