Qashqai J11. Steering control system

EPS CONTROL UNIT

STC-17

< ECU DIAGNOSIS INFORMATION >

STC

*1: Almost in accordance with the value of “MOTOR SIG”. It is not a malfunction though these values are not
accorded when steering quickly.
*2: Normally displays 100%. In case of an excessive stationary steering, the assist curvature gradually falls.
However, it returns to 100% when left standing.
*3: It is not a malfunction, though it might not be corresponding just after ignition switch in turned ON.

TERMINAL LAYOUT

PHYSICAL VALUES

STOP/START STATUS

When stop/start system is inactive

INACT

When stop/start system is restarting

AUTO ST

When stop/start system is active

ACT

When stop/start system is interrupted

CANCEL

IPA ON

When EPS system operation conditions are not satisfied

Off1

When there is a malfunction in EPS system or Intelligent Parking
Assist

Off2

When assist torque is larger than command value from Intelligent
Parking Assist

Off3

Normal

IPA STATUS 1

When Intelligent Parking Assist is active

When Intelligent Parking Assist is inactive

Off

STOP/START SYSTEM

When stop/start system is active

When stop/start system is prohibited

Off

IPA STATUS 2

When Intelligent Parking Assist is inactive

Off

When Intelligent Parking System is active (steering wheel is not
turned)

On1

The following cases
• When Intelligent Parking Assist is active
• When steering wheel is turned

On2

IPA STATUS 3

When Intelligent Parking Assist is normal

NORMAL

When Intelligent Parking Assist malfunction occurs

MALF

IPA TARGET CURRENT

When Intelligent Parking Assist is active

0 – 70 (A)

EPS CONTROL CUR-
RENT

When EPS system is active

0 – 90 (A)

Monitor item

Data monitor

Condition

Display value

JSGIA1434ZZ

STC-18

< ECU DIAGNOSIS INFORMATION >

EPS CONTROL UNIT

Fail-safe

INFOID:0000000010452107

• If any malfunction occurs in the system and control unit detects the malfunction, power steering warning

lamp on combination meter turns ON to indicate system malfunction.

• When power steering warning lamp is ON, the system enters into a manual steering state. (Control turning

force steering wheel becomes heavy.)

Protection Function

INFOID:0000000010452108

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.

DTC Inspection Priority Chart

INFOID:0000000010452109

When multiple DTCs are detected simultaneously, check one by one depending on the following priority list.

Terminal No.

(Wire Color)

Description

Condition

Value

(Approx.)

−

Signal name

Input/Output

(P)

—

CAN-L

Input/Output

—

(L)

—

CAN-H

Input/Output

—

(SB)

Ground

Ignition power supply

Input

Ignition switch: ON

10.5 V – 16 V

Ignition switch: OFF

0 V

(R)

Ground

Battery power supply

Input

Always

10.5 V – 16 V

(B)

Ground

—

Always

0 V

DTC

Fail-safe condition

C1601

The assist force is reduced according to the voltage, eventually ending with manual steering state

C1604

Manual steering state

C1606

C1607

C1608

C1609

Non-speed sensitive steering assist

U1000

• Non-speed sensitive steering assist
• Intelligent Parking Assist function (controlled from around view monitor) or Stop/Start system function (controlled

from ECM) is stopped

U1010

Normal control

U1970

Intelligent Parking Assist function (controlled from around view monitor) is stopped

Priority

Priority order item (DTC)

• U1000 CAN COMM CIRCUIT
• U1010 CONTROL UNIT(CAN)

• U1970 AVM
• C1609 CAN VHCL SPEED

C1601 BATTERY BOLT

• C1604 TORQUE SENSOR
• C1606 EPS MOTOR
• C1607 EPS EEPROM
• C1608 CONTROL UNIT

EPS CONTROL UNIT

STC-19

< ECU DIAGNOSIS INFORMATION >

STC

DTC Index

INFOID:0000000010452110

*: Even if DTC is detected, power steering warning lamp does not turns ON when assist torque is generated.
NOTE:
If two or more DTCs are detected, refer to

STC-18, "DTC Inspection Priority Chart"

DTC

Items (CONSULT screen terms)

Power steering

warning lamp

Reference

C1601

BATTERY VOLT

STC-25, "DTC Logic"

C1604

TORQUE SENSOR

STC-28, "DTC Logic"

C1606

EPS MOTOR

STC-29, "DTC Logic"

C1607

EEPROM

OFF

STC-30, "DTC Logic"

C1608

CONTROL UNIT

ON/OFF*

STC-30, "DTC Logic"

C1609

CAN VHCL SPEED

OFF

STC-31, "DTC Logic"

U1000

CAN COMM CIRCUIT

OFF

STC-32, "DTC Logic"

U1010

CONTROL UNIT(CAN)

OFF

STC-33, "DTC Logic"

U1970

AVM

OFF

STC-34, "DTC Logic"

STC-22

< BASIC INSPECTION >

DIAGNOSIS AND REPAIR WORK FLOW

BASIC INSPECTION

DIAGNOSIS AND REPAIR WORK FLOW

Work Flow

INFOID:0000000010452112

DETAILED FLOW

INTERVIEW FROM THE CUSTOMER

Clarify customer complaints before inspection. First of all, perform an interview utilizing

STC-23, "Diagnostic

Work Sheet"

and reproduce symptoms as well as fully understand it. Ask customer about his/her complaints

carefully. Check symptoms by driving vehicle with customer, if necessary.
NOTE:
Customers are not professional. Never guess easily like “maybe the customer means that...,” or “maybe the
customer mentions this symptom”.

>> GO TO 2.

CHECK SYMPTOM

Reproduce the symptom that is indicated by the customer, based on the information from the customer
obtained by interview. Also check that the symptom is not caused by protection function. Refer to

STC-18,

"Protection Function"

NOTE:
When the symptom is caused by normal operation, fully inspect each portion and obtain the understanding of
customer that the symptom is not caused by a malfunction.

>> GO TO 3.

PERFORM SELF-DIAGNOSIS

With CONSULT

Perform self-diagnosis.
Is any DTC detected?

YES

>> Record or print DTC freeze frame data (FFD). GO TO 4.

>> GO TO 6.

RECHECK SYMPTOM

With CONSULT

Erase self-diagnostic results.

Perform DTC confirmation procedures for the error detected system.

NOTE:
If some DTCs are detected at the same time, determine the order for performing the diagnosis based on

STC-

18, "DTC Inspection Priority Chart"

Is any DTC detected?

YES

>> GO TO 5.

>> Check harness and connectors based on the information obtained by interview. Refer to

GI-44,

"Intermittent Incident"

REPAIR OR REPLACE ERROR-DETECTED PARTS

• Repair or replace error-detected parts.
• Reconnect part or connector after repairing or replacing.
• When DTC is detected, erase self-diagnostic results for “EPS”.

>> GO TO 7.

IDENTIFY ERROR-DETECTED SYSTEM BY SYMPTOM DIAGNOSIS

Estimate error-detected system based on symptom diagnosis and perform inspection.
Can the error-detected system be identified?

DIAGNOSIS AND REPAIR WORK FLOW

STC-23

< BASIC INSPECTION >

STC

YES

>> GO TO 7.

>> Check harness and connectors based on the information obtained by interview. Refer to

GI-44,

"Intermittent Incident"

FINAL CHECK

With CONSULT

Check the reference value for EPS control unit.

Recheck the symptom and check that symptom is not reproduced on the same conditions.

Is the symptom reproduced?

YES

>> GO TO 3.

>> INSPECTION END

Diagnostic Work Sheet

INFOID:0000000010452113

Description

• In general, customers have their own criteria for a problem. Therefore, it is important to understand the

symptom and status well enough by asking the customer about his/her concerns carefully. To systemize all
the information for the diagnosis, prepare the interview sheet referring to the interview points.

• In some cases, multiple conditions that appear simultaneously may cause a DTC to be detected.

Interview sheet sample

Interview sheet

Customer
name

MR/MS

Registration
number

Initial year
registration

Vehicle type

VIN

Storage date

Engine

Mileage

km (Mile)

Symptom

The steering wheel position (center) is in the wrong position.

Power steering warning lamp turns on.

Noise

Vibration

Others

(

)

First occurrence

Recently

Others (

)

Frequency of occurrence

Always

Under a certain conditions of

Sometimes (time(s)/day)

Climate con-
ditions

Irrelevant

Weather

Fine

Cloud

Rain

Snow

Others (

)

Temperature

Hot

Warm

Cool

Cold

Temperature [Approx.

C (

F)]

Relative humidity

High

Moderate

Low

Road conditions

Urban area

Suburb area

High way

Mounting road (uphill or down hill)

Rough road

Operation conditions, etc.

Irrelevant

When engine starts

During idling

During driving

During acceleration

At constant speed driving

During deceleration

During cornering (right curve or left curve)

During steering

C1601 BATTERY POWER SUPPLY

STC-25

< DTC/CIRCUIT DIAGNOSIS >

STC

DTC/CIRCUIT DIAGNOSIS

C1601 BATTERY POWER SUPPLY

DTC Logic

INFOID:0000000010452114

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

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.

DTC REPRODUCTION PROCEDURE

With CONSULT

Turn the ignition switch OFF to ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1601” detected?

YES

>> Proceed to diagnosis procedure. Refer to

STC-25, "Diagnosis Procedure"

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010452115

CHECK EPS CONTROL UNIT GROUND CIRCUIT

Turn ignition switch OFF.

Disconnect EPS control unit harness connector.

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

Is the inspection result normal?

YES

>> GO TO 2.

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

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (1)

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

Turn ignition switch ON.

CAUTION:

Never start the engine.

Check voltage between EPS control unit harness connector and ground.

DTC

Display item

Malfunction detected condition

Possible cause

C1601

BATTERY VOLT

When a power supply voltage to the EPS control unit
is maintained at 16 V or more or at less than 9 V con-
tinuously for 0.5 second or more.

• Harness or connector
• EPS control unit (steering

column assembly)

• Fuse
• Power supply system
• Battery

EPS control unit

—

Continuity

Connector

Terminal

M34

Ground

Existed

EPS control unit

—

Voltage

Connector

Terminal

M33

Ground

Approx. 0 V

STC-26

< DTC/CIRCUIT DIAGNOSIS >

C1601 BATTERY POWER SUPPLY

Is the inspection result normal?

YES

>> GO TO 4.

>> GO TO 3.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (2)

Turn ignition switch OFF.

Check the 10A fuse (#4).

Check continuity between EPS control unit harness connector terminal and fuse block (J/B) harness con-
nector terminal.

Is the inspection result normal?

YES

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

PG-59, "Wiring Diagram -

IGNITION POWER SUPPLY -"

>> Repair or replace error-detected parts.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (3)

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

Turn ignition switch ON.

CAUTION:

Never start the engine.

Check voltage between EPS control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 6.

>> GO TO 5.

CHECK EPS CONTROL UNIT POWER SUPPLY CIRCUIT (4)

Turn ignition switch OFF.

Check the 50A fusible link (#F).

Check the 50A fusible link (#H).

Check the harness for open or short between EPS control unit harness connector No.9 terminal and the
50A fusible link (#F).

Check the harness for open or short between EPS control unit harness connector No.9 terminal and the
50A fusible link (#H).

Is the inspection result normal?

YES

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

PG-11, "Wiring Diagram - BAT-

TERY POWER SUPPLY -"

>> Repair or replace error-detected parts.

CHECK CONNECTOR

EPS control unit

—

Voltage

Connector

Terminal

M33

Ground

10.5 – 16 V

EPS control unit

Fuse block (J/B)

Continuity

Connector

Terminal

Connector

Terminal

M33

M76

Existed

EPS control unit

—

Voltage

Connector

Terminal

E34

Ground

10.5 – 16 V

EPS control unit

—

Voltage

Connector

Terminal

E34

Ground

10.5 – 16 V

STC-28

< DTC/CIRCUIT DIAGNOSIS >

C1604 TORQUE SENSOR

C1604 TORQUE SENSOR

DTC Logic

INFOID:0000000010452116

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

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.

DTC REPRODUCTION PROCEDURE

With CONSULT

Turn the ignition switch OFF to ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1604” detected?

YES

>> Proceed to diagnosis procedure. Refer to

STC-28, "Diagnosis Procedure"

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010452117

CHECK CONNECTOR

Check the EPS control unit pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

YES

>> GO TO 2.

>> Repair or replace error-detected parts.

PERFORM SELF-DIAGNOSIS

With CONSULT

Turn the ignition switch OFF to ON.

Erase self-diagnosis results for “EPS/DAST 3”.

Turn the ignition switch OFF and wait at least 10 seconds or more.

Turn the ignition switch ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1604” detected?

YES

>> Replace steering column assembly. Refer to

STC-46, "Removal and Installation"

>> Check EPS control unit pin terminals for damage or loose connection with harness connector. If

any item are damaged, repair or replace error-detected parts.

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 (steering

column assembly)

C1606 EPS MOTOR

STC-29

< DTC/CIRCUIT DIAGNOSIS >

STC

C1606 EPS MOTOR

DTC Logic

INFOID:0000000010452118

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

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.

DTC REPRODUCTION PROCEDURE

With CONSULT

Turn the ignition switch OFF to ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1606” detected?

YES

>> Proceed to diagnosis procedure. Refer to

STC-29, "Diagnosis Procedure"

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010452119

CHECK CONNECTOR

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

YES

>> GO TO 2.

>> Repair or replace error-detected parts.

PERFORM SELF-DIAGNOSIS

With CONSULT

Turn the ignition switch OFF to ON.

Erase self-diagnosis results for “EPS/DAST 3”.

Turn the ignition switch OFF and wait at least 10 seconds or more.

Turn the ignition switch ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1606” detected?

YES

>> Replace steering column assembly. Refer to

STC-46, "Removal and Installation"

>> Check EPS control unit pin terminals for damage or loose connection with harness connector. If

any item are damaged, repair or replace error-detected parts.

DTC

Display item

Malfunction detected condition

Possible cause

C1606

EPS MOTOR

When the motor driver malfunction of EPS control
unit or EPS motor malfunction is detected.

• Harness or connector
• EPS motor (steering column

assembly)

• EPS control unit (steering

column assembly)

STC-30

< DTC/CIRCUIT DIAGNOSIS >

C1607, C1608 EPS CONTROL UNIT

C1607, C1608 EPS CONTROL UNIT

DTC Logic

INFOID:0000000010452121

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

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.

DTC REPRODUCTION PROCEDURE

With CONSULT

Turn the ignition switch OFF to ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1607” or “C1608” detected?

YES

>> Proceed to diagnosis procedure. Refer to

STC-30, "Diagnosis Procedure"

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010452122

CHECK CONNECTOR

Check the EPS control unit pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

YES

>> GO TO 2.

>> Repair or replace error-detected parts.

PERFORM SELF-DIAGNOSIS

With CONSULT

Turn the ignition switch OFF to ON.

Erase self-diagnosis results for “EPS/DAST 3”.

Turn the ignition switch OFF and wait at least 10 seconds or more.

Turn the ignition switch ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1607” or “C1608” detected?

YES

>> Replace steering column assembly. Refer to

STC-46, "Removal and Installation"

>> Check EPS control unit pin terminals for damage or loose connection with harness connector. If

any item are damaged, repair or replace error-detected parts.

DTC

Display item

Malfunction detected condition

Possible cause

C1607

EEPROM

When the memory (EEPROM) system malfunction is
detected in EPS control unit.

EPS control unit (steering col-
umn assembly)

C1608

CONTROL UNIT

When the internal malfunction is detected in EPS
control unit.

C1609 VEHICLE SPEED SIGNAL

STC-31

< DTC/CIRCUIT DIAGNOSIS >

STC

C1609 VEHICLE SPEED SIGNAL

DTC Logic

INFOID:0000000010452124

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

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.

DTC REPRODUCTION PROCEDURE

With CONSULT

Turn the ignition switch OFF to ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1609” detected?

YES

>> Proceed to diagnosis procedure. Refer to

STC-31, "Diagnosis Procedure"

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010452125

PERFORM ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS

With CONSULT

Turn the ignition switch OFF to ON.

Perform “ABS” self-diagnosis.

Is any DTC detected?

YES

>> Check the DTC. Refer to

BRC-54, "DTC Index"

>> GO TO 2.

PERFORM SELF-DIAGNOSIS

With CONSULT

Turn the ignition switch OFF to ON.

Erase self-diagnosis results for “EPS/DAST 3”.

Turn the ignition switch OFF and wait at least 10 seconds or more.

Turn the ignition switch ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “C1609” detected?

YES

>> Replace steering column assembly. Refer to

STC-46, "Removal and Installation"

>> Check EPS control unit pin terminals for damage or loose connection with harness connector. If

any item are damaged, repair or replace error-detected parts.

DTC

Display item

Malfunction detected condition

Possible cause

C1609

CAN VHCL SPEED

A malfunction is detected in the vehicle speed signal
received with CAN communication.

• Harness or connector (CAN

communication line)

• EPS control unit (steering

column assembly)

• ABS actuator and electric

unit (control unit)

• Vehicle speed signal error

STC-32

< DTC/CIRCUIT DIAGNOSIS >

U1000 CAN COMM CIRCUIT

U1000 CAN COMM CIRCUIT

DTC Logic

INFOID:0000000010452130

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

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.

DTC REPRODUCTION PROCEDURE

With CONSULT

Turn the ignition switch OFF to ON.

Perform “EPS/DAST 3” self-diagnosis.

Is DTC “U1000” detected?

YES

>> Proceed to diagnosis procedure. Refer to

STC-32, "Diagnosis Procedure"

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010452131

Proceed to

LAN-28, "Trouble Diagnosis Flow Chart"

DTC

Display item

Malfunction detected condition

Possible cause

U1000

CAN COMM CIRCUIT

EPS control unit is not transmitting/re-
ceiving CAN communication signal for 2
seconds or more.

CAN communication error

Qashqai J11. Steering control system - part 2