Nissan Sentra. Manual - part 431

EC-420

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P2096, P2097 A/F SENSOR 1

3.

CHECK FOR EXHAUST GAS LEAK

1. Start engine and run it at idle.

2. Listen for an exhaust gas leak before the three way catalyst 2.
Is exhaust gas leak detected?

YES

>> Repair or replace malfunctioning parts.

NO

>> GO TO 4.

4.

CHECK FOR INTAKE AIR LEAK

1. Reconnect A/F sensor 1 harness connector.

2. Start engine and run it at idle.

3. Listen for an intake air leak after the mass air flow sensor.
Is intake air leak detected?

YES

>> Repair or replace malfunctioning parts.

NO

>> GO TO 5.

5.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1. Clear the mixture ratio self-learning value. Refer to 

EC-142, "Work Procedure"

.

2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0172 detected? Is it difficult to start engine?

YES

>> Perform trouble diagnosis for DTC P0171 or P0172. Refer to 

EC-246, "DTC Logic"

 or 

EC-250,

"DTC Logic"

.

NO

>> GO TO 6.

6.

CHECK A/F SENSOR 1 POWER SUPPLY

1. Turn ignition switch OFF.

2. Disconnect A/F sensor 1 harness connector.

3. Turn ignition switch ON.

4. Check the voltage between A/F sensor 1 harness connector and ground.

*1: Except California

*2: For California

Is the inspection result normal?

YES

>> GO TO 8.

NO

>> GO TO 7.

7.

CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect IPDM E/R harness connector.

3. Check the continuity between A/F sensor 1 harness connector and IPDM E/R harness connector.

*1: Except California

*2: For California

4. Also check harness for short to ground.

+

-

Voltage

A/F sensor 1

Connector

Terminal

F12

*1

F42

*2

4

Ground

Battery voltage

+

−

Continuity

A/F sensor 1

IPDM E/R

Connector

Terminal

Connector

Terminal

F12

*1

F42

*2

4

E45

26

Existed

P2096, P2097 A/F SENSOR 1

EC-421

< DTC/CIRCUIT DIAGNOSIS >

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Is the inspection result normal?

YES

>> Perform the trouble diagnosis for power supply circuit.

NO

>> Repair or replace error-detected parts.

8.

CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

*1: Except California

*2: For California

4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector

and ground.

*1: Except California

*2: For California

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

YES

>> GO TO 9.

NO

>> Repair or replace error-detected parts.

9.

CHECK A/F SENSOR 1 HEATER

Check the A/F sensor 1 heater. Refer to 

EC-177, "Component Inspection (A/F Sensor 1 Heater)"

.

Is the inspection result normal?

YES

>> GO TO 10.

NO

>> GO TO 12.

10.

CHECK HEATED OXYGEN SENSOR 2

Check heated oxygen sensor 2. Refer to 

EC-223, "Component Inspection (HO2S2)"

.

Is the inspection result normal?

YES

>> GO TO 11.

NO

>> Replace heated oxygen sensor 2. Refer to 

EX-5, "Exploded View"

.

11.

CHECK INTERMITTENT INCIDENT

Perform 

GI-39, "Intermittent Incident"

.

Is the inspection result normal?

+

−

Continuity

A/F sensor 1

ECM

Connector

Terminal

Connector

Terminal

F12

*1

F42

*2

1

F24

41

Existed

2

45

+

-

Continuity

A/F sensor 1

Connector

Terminal

F12

*1

F42

*2

1

Ground

Not existed

2

+

-

Continuity

ECM

Connector

Terminal

F24

41

Ground

Not existed

45

EC-422

< DTC/CIRCUIT DIAGNOSIS >

[MRA8DE]

P2096, P2097 A/F SENSOR 1

YES

>> GO TO 12.

NO

>> Repair or replace error-detected parts.

12.

REPLACE AIR FUEL RATIO (A/F) SENSOR 1

Replace air fuel ratio (A/F) sensor 1. Refer to 

EM-30, "Exploded View"

.

CAUTION:

• Discard any sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard

surface such as a concrete floor; use a new one.

• Before installing new sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner

[commercial service tool (J-43897-18 or J-43897-12)] and approved Anti-seize Lubricant (commercial

service tool).

Do you have CONSULT?

YES

>> GO TO 13.

NO

>> GO TO 14.

13.

CONFIRM A/F ADJUSTMENT DATA

With CONSULT

1. Turn ignition switch ON.

2. Select “A/F ADJ-B1” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

3. Make sure that “0.000” is displayed on CONSULT screen.
Is “0.000” displayed?

YES

>> INSPECTION END

NO

>> GO TO 14.

14.

CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

Clear the mixture ratio self-learning value. Refer to 

EC-142, "Work Procedure"

.

Do you have CONSULT?

YES

>> GO TO 15.

NO

>> INSPECTION END

15.

CONFIRM A/F ADJUSTMENT DATA

With CONSULT

1. Turn ignition switch ON.

2. Select “A/F ADJ-B1” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

3. Make sure that “0.000” is displayed on CONSULT screen.

>> INSPECTION END

P2100, P2103 THROTTLE CONTROL MOTOR RELAY

EC-423

< DTC/CIRCUIT DIAGNOSIS >

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P2100, P2103 THROTTLE CONTROL MOTOR RELAY

DTC Logic

INFOID:0000000009758679

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next test.

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

2. Turn ignition switch ON.

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

TESTING CONDITION:

Before performing the following procedure, confirm that battery voltage is more than 8 V.
Witch DTC is detected?

P2100 >> GO TO 2.

P2103 >> GO TO 3.

2.

PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P2100

1. Turn ignition switch ON and wait at least 2 seconds.

2. Start engine and let it idle for 5 seconds.

3. Check DTC.
Is DTC detected?

YES

>> Proceed to 

EC-423, "Diagnosis Procedure"

.

NO

>> INSPECTION END

3.

PERFORM DTC CONFIRMATION PROCEDURE FOR DTC P2103

1. Turn ignition switch ON and wait at least 1 second.

2. Check DTC.
Is DTC detected?

YES

>> Proceed to 

EC-423, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000009758680

1.

CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY

1. Turn ignition switch OFF.

2. Check the voltage between ECM harness connector and ground.

DTC No.

CONSULT screen terms

(Trouble diagnosis con-

tent)

DTC detecting condition

Possible cause

P2100

ETC MOT PWR-B1
(Throttle actuator “A” 
control motor circuit/
open)

ECM detects a voltage of power source for 
throttle control motor is excessively low.

• Harness or connectors

(Throttle control motor relay circuit is 
open)

• Throttle control motor relay

P2103

ETC MOT PWR
(Throttle actuator “A” 
control motor circuit 
high)

ECM detect the throttle control motor relay is 
stuck ON.

• Harness or connectors

(Throttle control motor relay circuit is 
shorted)

• Throttle control motor relay

+

−

Voltage

ECM

Connector

Terminal

Connector

Terminal

F24

21

E16

128

Battery voltage