Nissan Sentra B18 (2020-2025) Service Manual / Steering / Steering Control System :: Symptom Diagnosis

Nissan Sentra B18 (2020-2025) Service Manual: Steering Control System :: Symptom Diagnosis

Eps Warning Lamp Does Not Turn on. Description

Description

EPS warning lamp does not turn ON when the ignition switch is ON. (Check the illumination of the EPS warning lamp.)

Diagnosis Procedure

CHECK EPS WARNING LAMP
1. Perform the trouble diagnosis of EPS warning lamp. Refer to Diagnosis Procedure.
Is the inspection result normal?
YES>>
Check that there is no malfunction in each harness connector pin terminal or disconnection.
NO>>
Repair or replace the specific malfunctioning part.

Eps Warning Lamp Does Not Turn Off. Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

PERFORM SELF DIAGNOSTIC RESULT
1. CONSULT
  1. Ignition switch ON.
  2. Select “Self Diagnostic Result” mode of “EPS/DAST 3”.
Is any DTC detected?
YES >>
Check the DTC. Refer to DTC Index.
NO >>
GO TO 2.
CHECK EPS WARNING LAMP
1. Perform the trouble diagnosis of EPS warning lamp. Refer to Diagnosis Procedure.
Is the inspection result normal?
YES>>
GO TO 3.
NO>>
Repair or replace the specific malfunctioning part.
CHECK EPS CONTROL UNIT POWER SUPPLY AND GROUND CIRCUIT
1. Perform the trouble diagnosis of EPS control unit power supply and ground. Refer to Diagnosis Procedure.
Is the inspection result normal?
YES >>
Check that there is no malfunction in each harness connector pin terminal or disconnection.
NO >>
Repair or replace the specific malfunctioning part.

Steering Wheel Turning Force Is Heavy or Light. Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

PERFORM SELF DIAGNOSTIC RESULT
1. CONSULT
  1. Ignition switch ON.
  2. Select “Self Diagnostic Result” mode of “EPS/DAST 3”.
Is any DTC detected?
YES >>
Check the DTC. Refer to DTC Index.
NO >>
GO TO 2.
CHECK THE ILLUMINATION OF THE EPS WARNING LAMP
1. 1. Ignition switch ON.
  2. Check that the EPS warning lamp 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 Diagnosis Procedure.
CHECK EPS CONTROL UNIT SIGNAL (1)
1. CONSULT
  1. Start the engine.
    
    CAUTION:
    
    Never drive the Nissan Sentra vehicle.
  2. Select “Assist level” in “Data Monitor” mode of “EPS/DAST 3”.
Does the item in “Data Monitor” indicate “100%”?
YES >>
GO TO 6.
NO >>
GO TO 4.
CHECK EPS CONTROL UNIT SIGNAL (2)
1. CONSULT
  
  Select “Battery voltage” in “Data Monitor” mode of “EPS/DAST 3”.
Does the item in “Data Monitor” indicate “10.5 V” or more?
YES >>
GO TO 5.
NO >>
Perform trouble diagnosis of EPS control unit power supply and ground. Refer to Diagnosis Procedure.
CHECK EPS CONTROL UNIT SIGNAL (3)
1. CONSULT
  1. Select “Assist level” in “Data Monitor” mode of “EPS/DAST 3”.
  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 malfunction. Inspection End.

CHECK EPS CONTROL UNIT SIGNAL (4)

CONSULT

Start the engine.

CAUTION:

Never drive the Nissan Sentra vehicle.
Turn steering wheel from full left stop to full right stop.

Select “Steering torque” in “Data Monitor” mode of “EPS/DAST 3”.

Monitor item	Condition	Display value
STEERING TORQUE	Steering wheel: Not steering (There is no steering force)	Approx. 0 Nm
	Steering wheel: Right turn	Positive value (Nm)
	Steering wheel: Left turn	Negative value (Nm)

Is the inspection result normal?

YES >>

GO TO 8.

NO >>

GO TO 7.

CHECK EPS MOTOR
1. Perform the trouble diagnosis of EPS motor. Refer to DTC Diagnosis Procedure.
Is the inspection result normal?
YES >>
GO TO 8.
NO >>
Repair or replace the specific malfunctioning part.
CHECK STEERING WHEEL TURNING FORCE
1. Check the steering wheel turning force. Refer to Inspection.
Is the inspection result normal?
YES >>
Inspection End.
NO >>
Check the steering wheel turning force for mechanical malfunction. Refer to Inspection.

Unbalance Steering Wheel Turning Force and Return Between Right and Left. Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

CHECK THE ILLUMINATION OF THE EPS WARNING LAMP
1. Check the EPS warning lamp while engine is running.
Does the EPS warning lamp turn OFF?
YES>>
GO TO 2.
NO>>
Refer to Diagnosis Procedure.
CHECK WHEEL ALIGNMENT
1. 1. Check the wheel alignment. Refer to Wheel Alignment (Unladen1).
  2. Select “Self Diagnostic Result” mode of “EPS/DAST 3”.
Is the inspection result normal?
YES>>
GO TO 3.
NO>>
Adjustment of wheel alignment. Refer to Wheel Alignment (Unladen1).

CHECK EPS CONTROL UNIT SIGNAL

CONSULT

Start the engine.

CAUTION:

Never drive the Nissan Sentra vehicle.
Turn steering wheel from full left stop to full right stop.
Select “Steering torque” in “Data Monitor” mode of “EPS/DAST 3”.

Perform the torque sensor inspection.

Monitor item	Condition	Display value
STEERING TORQUE	Steering wheel: Not steering (There is no steering force)	Approx. 0 Nm
	Steering wheel: Right turn	Positive value (Nm)
	Steering wheel: Left turn	Negative value (Nm)

Is the inspection result normal?

YES>>

GO TO 5.

NO>>

GO TO 4.

CHECK EPS MOTOR
1. Perform the trouble diagnosis of EPS motor. Refer to DTC Diagnosis Procedure.
Is the inspection result normal?
YES>>
GO TO 5.
NO>>
Repair or replace the specific malfunctioning part.
CHECK STEERING WHEEL TURNING FORCE
1. Check the steering wheel turning force. Refer to Inspection.
Is the inspection result normal?
YES>>
Inspection End.
NO>>
Check the steering wheel turning force for mechanical malfunction. Refer to Inspection.

Unbalance Steering Wheel Turning Force (torque Variation). Diagnosis Procedure. Diagnosis Procedure

Diagnosis Procedure

PERFORM SELF DIAGNOSTIC RESULT
1. CONSULT
  1. Ignition switch ON.
  2. Select “Self Diagnostic Result” mode of “EPS/DAST 3”.
Is any DTC detected?
YES >>
Check the DTC. Refer to DTC Index.
NO >>
GO TO 2.
CHECK THE ILLUMINATION OF THE EPS WARNING LAMP
1. Check the EPS warning lamp while the engine is started.
Does the EPS warning lamp turn OFF?
YES>>
GO TO 3.
NO>>
Refer to Diagnosis Procedure.
CHECK STEERING COLUMN AND STEERING GEAR
1. Check the steering column assembly and steering gear assembly.
  - Steering column assembly. Refer to Inspection.
  - Steering gear assembly. Refer to Inspection.
Is the inspection result normal?
YES >>
GO TO 4.
NO >>
Repair or replace the specific malfunctioning part.
CHECK EPS CONTROL UNIT SIGNAL (1)
1. CONSULT
  1. Start the engine.
    
    CAUTION:
    
    Never drive the Nissan Sentra vehicle.
  2. Turn steering wheel from full left stop to full right stop.
  3. Select “Assist level” in “Data Monitor” mode of “EPS/DAST 3”.
Does the item in “Data Monitor” maintain “100%”?
YES >>
GO TO 7.
NO >>
GO TO 5.
CHECK EPS CONTROL UNIT SIGNAL (2)
1. CONSULT
  
  Select “Battery voltage” in “Data Monitor” mode of “EPS/DAST 3”.
Does the item in “Data Monitor” indicate “10.5 V” or more?
YES >>
GO TO 6.
NO >>
Perform trouble diagnosis of EPS control unit power supply and ground. Refer to Diagnosis Procedure.
CHECK EPS CONTROL UNIT SIGNAL (3)
1. CONSULT
  1. Select “Assist level” in “Data Monitor” mode of “EPS/DAST 3”.
  2. Stop the EPS system until the item in “Data Monitor” becomes “100%” or less.
    Note:
    While stopping the EPS system, do not turn steering wheel.
  3. Check that the symptom continues.
Does the symptom continue?
YES >>
GO TO 7.
NO >>
The assist torque decreases because of protection function. This is not malfunction. Inspection End.

CHECK EPS CONTROL UNIT SIGNAL (4)

CONSULT

Start the engine.

CAUTION:

Never drive the Nissan Sentra vehicle.
Turn steering wheel from full left stop to full right stop.
Select “Steering torque” in “Data Monitor” mode of “EPS/DAST 3”.

Perform the torque sensor inspection.

Monitor item	Condition	Display value
STEERING TORQUE	Steering wheel: Not steering (There is no steering force)	Approx. 0 Nm
	Steering wheel: Right turn	Positive value (Nm)
	Steering wheel: Left turn	Negative value (Nm)

Is the inspection result normal?

YES >>

GO TO 9.

NO >>

GO TO 8.

CHECK EPS MOTOR
1. Perform the trouble diagnosis of EPS motor. Refer to DTC Diagnosis Procedure.
Is the inspection result normal?
YES >>
GO TO 9.
NO >>
Repair or replace the specific malfunctioning part.
CHECK STEERING WHEEL TURNING FORCE
1. Check the steering wheel turning force. Refer to Inspection.
Is the inspection result normal?
YES >>
Inspection End.
NO >>
Check the steering wheel turning force for mechanical malfunction. Refer to Inspection.

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