Nissan X-Trail 32. Manual - part 1997

STC-38

< DTC/CIRCUIT DIAGNOSIS >

U1971 SONAR SYSTEM

U1971 SONAR SYSTEM

DTC Description

INFOID:0000000010698064

DTC DETECTION LOGIC

POSSIBLE CAUSE

• Harness or connector

(CAN communication line)

• EPS control unit (steering column assembly)
• Sonar control unit

FAIL-SAFE

Around view monitor with park assist function stops (controlled by sonar).

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/DAST 3” self-diagnosis.

Is DTC “U1971” detected?

YES

>> Proceed to diagnosis procedure. Refer to 

STC-38, "Diagnosis Procedure"

.

NO-1

>> To check malfunction symptom before repair: Refer to 

GI-44, "Intermittent Incident"

.

NO-2

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000010698065

1.

CHECK SONARCONTROL UNIT

1.

Turn ignition switch OFF.

2.

Disconnect sonar control unit harness connector.

3.

Check the sonar control unit pin terminals (CAN communication lines) for damage or loose connection
with harness connector.

Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Recheck terminals for damage or loose connection. Refer to

LAN-7, "Precautions for Harness

Repair"

.

2.

PERFORM SELF-DIAGNOSIS (SONAR CONTROL UNIT)

With CONSULT

1.

Connect sonar control unit harness connector.

2.

Connect EPS control unit harness connector.

3.

Erase self-diagnostic results for “SONAR”.

4.

Turn the ignition switch OFF, and then wait 10 seconds and more.

5.

Turn the ignition switch ON.

6.

Perform self-diagnosis for “SONAR”.

Is any DTC detected?

DTC

Display item

(Trouble diagnosis content)

Malfunction detected condition

U1971

SONAR
(Sonar)

CAN communication signal of sonar control unit is abnormal for 2 consecutive 
seconds or more.

U1971 SONAR SYSTEM

STC-39

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

YES

>> Check the DTC. Refer to 

SN-143, "DTC Index"

.

NO

>> GO TO 3.

3.

PERFORM SELF-DIAGNOSIS

With CONSULT

1.

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

2.

Turn the ignition switch OFF, and then wait 10 seconds and more.

3.

Turn the ignition switch ON.

4.

Perform the self-diagnosis of all systems.

Is DTC “U1000”,“U1971” or other DTC detected?

YES (“U1000”)>>Refer to 

LAN-17, "Trouble Diagnosis Flow Chart"

.

YES (“U1971”)>>Replace sonar control unit. Refer to 

SN-237, "Removal and Installation"

.

YES (Other DTC)>>Check the DTC.
NO

>> INSPECTION END

STC-40

< DTC/CIRCUIT DIAGNOSIS >

POWER SUPPLY AND GROUND CIRCUIT

POWER SUPPLY AND GROUND CIRCUIT

Diagnosis Procedure

INFOID:0000000010688432

1.

CHECK IGNITION POWER SUPPLY FOR EPS CONTROL UNIT

1.

Turn ignition switch OFF.

2.

Disconnect EPS control unit harness connector.

3.

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

4.

Turn ignition switch ON.

CAUTION:

Never start the engine.

5.

Check voltage between EPS control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 3.

NO

>> GO TO 2.

2.

CHECK IGNITION POWER SUPPLY CIRCUIT FOR EPS CONTROL UNIT

1.

Turn ignition switch OFF.

2.

Check the 10A fuse (#30).

3.

Check continuity between EPS control unit harness connector and the fuse block (J/B).

Is the inspection result normal?

YES

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

NO

>> Repair or replace error-detected parts.

3.

CHECK BATTERY POWER SUPPLY FOR EPS CONTROL UNIT

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 terminals and ground.

Is the inspection result normal?

EPS control unit

—

Voltage

Connector

Terminal

M37

4

Ground

Approx. 0 V

EPS control unit

—

Voltage

Connector

Terminal

M37

4

Ground

10.5 – 16 V

EPS control unit

Fuse block (J/B)

Continuity

Connector

Terminal

Connector

Terminal

M37

4

M3

7C

Existed

EPS control unit

—

Voltage

Connector

Terminal

M38

9

Ground

10.5 – 16 V

EPS control unit

—

Voltage

Connector

Terminal

M38

9

Ground

10.5 – 16 V

POWER SUPPLY AND GROUND CIRCUIT

STC-41

< DTC/CIRCUIT DIAGNOSIS >

C

D

E

F

H

I

J

K

L

M

A

B

STC

N

O

P

YES

>> GO TO 5.

NO

>> GO TO 4.

4.

CHECK BATTERY POWER SUPPLY CIRCUIT FOR EPS CONTROL UNIT

1.

Turn ignition switch OFF.

2.

Check the 50A fusible link (F). (Except for R9M engine models)

3.

Check the 50A fusible link (H). (Except for R9M engine models)

4.

Check the 50A fusible link (J). (For R9M engine models)

5.

Check the 50A fusible link (I). (For R9M engine models)

6.

Check the harness for open or short between EPS control unit harness connector No.9 terminal and the
50A fusible link (F). (Except for R9M engine models)

7.

Check the harness for open or short between EPS control unit harness connector No.9 terminal and the
50A fusible link (H). (Except for R9M engine models)

8.

Check the harness for open or short between EPS control unit harness connector No.9 terminal and the
50A fusible link (J). (For R9M engine models)

9.

Check the harness for open or short between EPS control unit harness connector No.9 terminal and the
50A fusible link (I). (For R9M engine models)

Is the inspection result normal?

YES

>> Perform the trouble diagnosis for power supply circuit.

NO

>> Repair or replace error-detected parts.

5.

CHECK EPS CONTROL UNIT GROUND CIRCUIT

Check continuity between EPS control unit harness connector and ground.

Is the inspection result normal?

YES

>> GO TO 6.

NO

>> Repair or replace error-detected parts.

6.

CHECK TERMINAL

1.

Turn ignition switch OFF.

2.

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

3.

Check fuse block (J/B) pin terminals for damage or loose connection with harness connector.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Repair or replace error-detected parts.

EPS control unit

—

Continuity

Connector

Terminal

M38

10

Ground

Existed