Nissan Sentra. Manual - part 829

C1601 BATTERY POWER SUPPLY

STC-23

< DTC/CIRCUIT DIAGNOSIS >

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2. Turn ignition switch ON.

CAUTION:

Never start the engine.

3. Check voltage between EPS control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> GO TO 3.

3.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (2)

1. Turn ignition switch OFF.

2. Check the 10A fuse (#5).

3. Check the harness for open or short between EPS control unit harness connector terminal 4 and the 10A

fuse (#5).

Is the inspection result normal?

YES

>> Perform the trouble diagnosis for ignition power supply circuit. Refer to 

PCS-70, "Wiring Dia-

gram"

.

NO

>> Repair or replace the malfunctioning parts.

4.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (3)

1. Turn ignition switch OFF.

2. Check voltage between EPS control unit harness connector terminals and ground.

3. Turn ignition switch ON.

CAUTION:

Never start the engine.

4. Check voltage between EPS control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> GO TO 5.

5.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (4)

1. Turn ignition switch OFF.

2. Check the 60A fusible link (#M).

3. Check the harness for open or short between EPS control unit harness connector terminal 9 and the 60A

fusible link (#M).

Is the inspection result normal?

YES

>> Perform the trouble diagnosis for power supply circuit. Refer to 

PCS-70, "Wiring Diagram"

.

NO

>> Repair or replace the malfunctioning parts.

EPS control unit

—

Voltage

Connector

Terminal

M87

4

Ground

Approx. 0 V

EPS control unit

—

Voltage

Connector

Terminal

M87

4

Ground

Battery voltage

EPS control unit

—

Voltage

Connector

Terminal

M37

9

Ground

Battery voltage

EPS control unit

—

Voltage

Connector

Terminal

M37

9

Ground

Battery voltage

STC-24

< DTC/CIRCUIT DIAGNOSIS >

C1601 BATTERY POWER SUPPLY

6.

CHECK TERMINALS AND HARNESS CONNECTORS

Check the EPS control unit pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?

YES

>> EPS control unit is malfunctioning. Replace steering column assembly. Refer to 

ST-12, "Removal

and Installation"

.

NO

>> Repair or replace the malfunctioning parts.

C1604 TORQUE SENSOR

STC-25

< DTC/CIRCUIT DIAGNOSIS >

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C1604 TORQUE SENSOR

DTC Logic

INFOID:0000000009757439

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC CONFIRMATION PROCEDURE has been previously conducted, always turn ignition switch OFF and

wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.

DTC REPRODUCTION PROCEDURE

With CONSULT

1. Turn the ignition switch OFF to ON.

2. Perform EPS self-diagnosis.
Is DTC “C1604” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-25, "Diagnosis Procedure"

.

NO

>> Inspection End.

Diagnosis Procedure

INFOID:0000000009757440

Regarding Wiring Diagram information, refer to 

STC-15, "Wiring Diagram"

.

1.

CHECK TORQUE SENSOR POWER SUPPLY CIRCUIT

1. Turn ignition switch ON.

2. Check voltage between EPS control unit harness connector terminals and ground.

CAUTION:

Steering wheel is neutral position. (There is no steering force.)

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Perform the trouble diagnosis for battery power supply circuit. Refer to 

STC-22, "Diagnosis Proce-

dure"

.

2.

CHECK TORQUE SENSOR GROUND CIRCUIT

1. Turn ignition switch OFF.

2. Check continuity between EPS control unit harness connector terminal and ground.

CAUTION:

Steering wheel is neutral position. (There is no steering force.)

DTC

Display item

Malfunction detected condition

Possible cause

C1604

TORQUE SENSOR

When torque sensor output signal is malfunctioning.

• Harness or connector
• Torque sensor
• EPS control unit

EPS control unit

—

Voltage

Connector

Terminal

M27

18

Ground

Approx. 5 V

STC-26

< DTC/CIRCUIT DIAGNOSIS >

C1604 TORQUE SENSOR

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair open circuit or short to ground or short to power in harness or connectors.

3.

CHECK TORQUE SENSOR SIGNAL

1. Turn ignition switch OFF to ON.

2. Check voltage between EPS control unit harness connector terminal and ground.

CAUTION:

Steering wheel is neutral position. (There is no steering force.)

3. Start the engine.

4. Check voltage between EPS control unit harness connector terminal and ground.

CAUTION:

Steering wheel is right or left turn.

Is the inspection result normal?

YES

>> GO TO 4.

NO

>> Torque sensor is malfunction. Replace steering column assembly. Refer to 

ST-12, "Removal and

Installation"

.

4.

CHECK CONNECTOR

1. Turn ignition switch OFF.

2. Disconnect EPS control unit harness connector.

3. Check terminal for deformation, disconnection, looseness, and so on. If any malfunction is found, repair or

replace terminal.

Is the inspection result normal?

YES

>> Replace EPS control unit. Refer to 

STC-39, "Removal and Installation"

.

NO

>> Repair or replace the malfunctioning parts.

EPS control unit

—

Continuity

Connector

Terminal

M27

15

Ground

Yes

EPS control unit

—

Voltage

Connector

Terminal

M27

17

Ground

Approx. 2.5 V

16

EPS control unit

—

Voltage

Connector

Terminal

M27

17

Ground

Approx. 1.6 V 

− 3.4 

V

(The value is 

changed accord-

ing to steering left 

or right)

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