Nissan Pathfinder. Manual - part 467

EC-174

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

POWER SUPPLY AND GROUND CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connectors.

3. Disconnect IPDM E/R harness connector.

4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground.
Is the inspection result normal?

YES

>> Perform the trouble diagnosis for power supply circuit.

NO

>> Repair or replace error-detected parts.

6.

CHECK ECM POWER SUPPLY (MAIN)-II

1. Turn ignition switch OFF and wait at least 10 seconds.

2. Check the voltage between ECM harness connector terminals as per the following.

Is the inspection result normal?

YES

>> GO TO 9.

NO

>> GO TO 7.

7.

CHECK ECM RELAY CONTROL SIGNAL

Check the voltage between ECM harness connector terminals as per the following.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-49, "Intermittent Incident"

.

NO

>> GO TO 8.

8.

CHECK ECM RELAY CONTROL SIGNAL CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Disconnect IPDM E/R harness connector.

4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground and to power.
Is the inspection result normal?

YES

>> Replace IPDM E/R. Refer to 

PCS-32, "Removal and Installation"

.

NO

>> Repair or replace error-detected parts.

+

−

Continuity

ECM

IPDM E/R

Connector

Terminal

Connector

Terminal

E16

121

E121

13

Existed

ECM

Condition

Voltage

(Approx.)

Connector

+

−

Terminal

E16

121

128

After turning ignition switch OFF, battery voltage will exist for a few seconds

Drop to 0 V

ECM

Condition

Voltage

(Approx.)

+

−

Connector

Terminal

Connector

Terminal

F51

31

E16

128

Ignition switch ON 

0 V

Turn ignition switch OFF and wait at least 10 seconds.

Battery voltage

+

−

Continuity

ECM

IPDM E/R

Connector

Terminal

Connector

Terminal

F51

31

F24

72

Existed

POWER SUPPLY AND GROUND CIRCUIT

EC-175

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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9.

CHECK IGNITION SWITCH SIGNAL

1. Turn ignition switch ON.

2. Check the voltage between ECM harness connector terminals.

Is the inspection result normal?

YES

>> GO TO 11.

NO

>> GO TO 10.

10.

CHECK IGNITION SWITCH SIGNAL CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Disconnect IPDM E/R harness connector.

4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground and to power.
Is the inspection result normal?

YES

>> Perform the trouble diagnosis for power supply circuit.

NO

>> Repair or replace error-detected parts.

11.

CHECK ECM POWER SUPPLY (BACK-UP)

Check the voltage between ECM harness connector terminals.

Is the inspection result normal?

YES

>> Check intermittent incident. Refer to 

GI-49, "Intermittent Incident"

.

NO

>> GO TO 12.

12.

CHECK ECM POWER SUPPLY (BACK-UP) CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Disconnect IPDM E/R harness connector.

4. Check the continuity between ECM harness connector and IPDM E/R harness connector.

5. Also check harness for short to ground.
Is the inspection result normal?

ECM

Condition

Voltage

(Approx.)

Connector

+

−

Terminal

E16

109

128

Ignition switch OFF

0 V

Ignition switch ON

Battery voltage

+

−

Continuity

ECM

IPDM E/R

Connector

Terminal

Connector

Terminal

E16

109

F19

55

Existed

ECM

Voltage

+

−

Connector

Terminal

Connector

Terminal

F51

26

E16

128

Battery voltage

+

−

Continuity

ECM

IPDM E/R

Connector

Terminal

Connector

Terminal

F51

26

F19

58

Existed

EC-176

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

POWER SUPPLY AND GROUND CIRCUIT

YES

>> Perform the trouble diagnosis for power supply circuit.

NO

>> Repair or replace error-detected parts.

U0101 CAN COMM CIRCUIT

EC-177

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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U0101 CAN COMM CIRCUIT

Description

INFOID:0000000009178097

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-

tiplex communication line with high data communication speed and excellent error detection ability. Many elec-

tronic control units are equipped onto a vehicle, and each control unit shares information and links with other

control units during operation (not independent). In CAN communication, control units are connected with 2

communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.

Each control unit transmits/receives data but selectively reads required data only.

DTC Logic

INFOID:0000000009178098

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON and wait at least 3 seconds.

2. Check DTC.
Is DTC detected?

YES

>> Proceed to 

EC-177, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009178099

Perform the trouble diagnosis for CAN communication system. Refer to 

LAN-20, "Trouble Diagnosis Flow

Chart"

.

DTC No.

CONSULT screen terms

(Trouble diagnosis content)

DTC detecting condition

Possible cause

U0101

LOST COMM (TCM)
(Lost Communication with TCM)

When ECM is not transmitting or receiving CAN 
communication signal of OBD (emission-related 
diagnosis) with TCM for 2 seconds or more.

• CAN communication line between 

TCM and ECM

• CAN communication line open or 

shorted