Nissan Qashqai (2007-2010). Manual - part 752

DIAGNOSIS SYSTEM (EPS CONTROL UNIT)

STC-7

< FUNCTION DIAGNOSIS >

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DIAGNOSIS SYSTEM (EPS CONTROL UNIT)

CONSULT-III Function (EPS)

INFOID:0000000000949820

FUNCTION

CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.

SELF-DIAG RESULTS MODE

Display Item List

Refer to 

STC-22, "DTC No. Index"

.

DATA MONITOR MODE

Display Item List

Diagnostic test mode

Function

Self-diagnostic results

Self-diagnostic results can be read and erased quickly.

Data monitor

Input/Output data in the EPS control unit can be read.

ECU part number

EPS control unit part number can be read.

CAN diagnostic support monitor

The results of transmit/receive diagnosis of CAN communication can be read.

Monitor item (Unit)

Remarks

BATTERY VOLT (V)

Displays the power supply voltage for EPS control unit.

TORQUE SENSOR (Nm)

Displays steering wheel turning force detected by torque sensor.

MOTOR SIG (A)

Displays the current commanded value to EPS motor.

MOTOR CURRENT (A)

Displays the current value consumed by EPS motor.

ASSIST TORQUE (Nm)

Displays assist torque being output by the electric power steering.

C/U TEMP (

°

C)

Displays the temperature of the EPS control unit.

ASSIST LEVEL (%)

Normally displays 100%. In case of an excessive stationary steering, the assist 
curvature gradually falls. However, it return to 100% when left standing.

VEHICLE SPEED (km/h) or (MPH)

Vehicle speed is displayed from vehicle speed signal with CAN communication.

WARNING LAMP (On/Off)

EPS warning lamp control status is displayed.

ENGINE STATUS (STOP/RUN)

Engine speed is displayed from engine status signal with CAN communication.

MOTOR TEMP (

°

C)

Displays the temperature of EPS motor.

VHCL SPD CALC (km/h) or (MPH)

Displays vehicle speeds used for controlling EPS.

STC-8

< COMPONENT DIAGNOSIS >

C1601 BATTERY POWER SUPPLY

COMPONENT DIAGNOSIS

C1601 BATTERY POWER SUPPLY

Description

INFOID:0000000000940491

Power is supplied from the battery to EPS control unit.

DTC Logic

INFOID:0000000000940492

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

CHECK SELF-DIAGNOSIS RESULTS

Check the self-diagnosis results.

Is above displayed on the self-diagnosis display?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-8, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000000940494

1.

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.

4.

Reconnect connector and then perform self-diagnosis. Refer to 

STC-7, "CONSULT-III Function (EPS)"

.

Is any item indicated on the self-diagnosis display?

YES

>> GO TO 2.

NO

>> Poor connection of connector terminal. Repair or replace connector.

2.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT

1.

Turn ignition switch OFF.

2.

Disconnect EPS control unit harness connector.

3.

Turn ignition switch ON. (Do not start engine.)

4.

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

5.

Turn ignition switch OFF.

6.

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

DTC

Display item

Malfunction detected condition

Possible cause

C1601

BATTERY VOLT

When the power supply malfunction supplied to EPS 
control unit is detected.

• Harness or connector
• EPS control unit

Self-diagnosis results

BATTERY VOLT

EPS control unit

—

Voltage

Connector

Terminal

M38

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Ground

Battery voltage

M37

10

C1601 BATTERY POWER SUPPLY

STC-9

< COMPONENT DIAGNOSIS >

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Is the inspection result normal?

YES

>> GO TO 3.

NO

>> Repair or replace malfunctioning components.

3.

CHECK EPS CONTROL UNIT GROUND CIRCUIT

1.

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

2.

Connect EPS control unit harness connector.

Is the inspection result normal?

YES

>> GO TO 4.

NO

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

4.

CHECK DTC

Start engine.

Does EPS warning lamp turn OFF?

YES

>> EPS control unit is malfunction. Replace steering column assembly.

NO

>> Perform self-diagnosis, repair or replace damaged parts.

Special Repair Requirement

INFOID:0000000000956134

1.

ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION

Always perform the neutral position adjustment for the steering angle sensor, when replacing the EPS control
unit. Refer to 

BRC-78, "ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION : Descrip-

tion"

. (With ESP models)

>> END

EPS control unit

—

Voltage

Connector

Terminal

M38

1

Ground

Battery voltage

M37

10

Approx. 0 V

EPS control unit

—

Continuity

Connector

Terminal

M38

2

Ground

Existed

STC-10

< COMPONENT DIAGNOSIS >

C1604 TORQUE SENSOR

C1604 TORQUE SENSOR

Description

INFOID:0000000000940497

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

DTC Logic

INFOID:0000000000940498

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

CHECK SELF-DIAGNOSIS RESULTS

Check the self-diagnosis results.

Is above displayed on the self-diagnosis display?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-10, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000000940499

1.

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.

4.

Reconnect connectors and then perform the self-diagnosis. Refer to 

STC-7, "CONSULT-III Function

(EPS)"

.

Is the “TORQUE SENSOR” [C1604] displayed?

YES

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

NO

>> Poor connection of connector terminal. Repair or replace connector.

Special Repair Requirement

INFOID:0000000000956143

1.

ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION

Always perform the neutral position adjustment for the steering angle sensor, when replacing the EPS control
unit. Refer to 

BRC-78, "ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION : Descrip-

tion"

. (With ESP models)

>> END

DTC

Display item

Malfunction detected condition

Possible cause

C1604

TORQUE SENSOR

Malfunction of the torque sensor in steering column 
assembly is detected.

• Harness or connector
• Torque sensor
• EPS control unit

Self-diagnosis results

TORQUE SENSOR