Nissan Frontier D22. Manual - part 329

DTC P1143 HO2S1

EC-419

[KA24DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

2. 

CLEAR THE SELF-LEARNING DATA.

 With CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.

3.

Clear the self-learning control coefficient by touching “CLEAR”.

4.

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

 Without CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF.

3.

Disconnect mass air flow sensor harness connector, and restart
and run engine for at least 3 seconds at idle speed.

4.

Stop engine and reconnect mass air flow sensor harness con-
nector.

5.

Make sure DTC P0102 is displayed.

6.

Erase the DTC memory. Refer to 

EC-61, "HOW TO ERASE

EMISSION-RELATED DIAGNOSTIC INFORMATION"

 .

7.

Make sure DTC P0000 is displayed.

8.

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

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0171. Refer to 

EC-225

 .

No

>> GO TO 3.

3. 

CHECK HEATED OXYGEN SENSOR 1 HEATER

Check resistance between terminals 3 and 1.

Check continuity between terminals 2 and 1, 3 and 2.

CAUTION:

Discard any heated oxygen 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.

OK or NG

OK

>> GO TO 4.

NG

>> Replace heated oxygen sensor 1.

SEF215Z

AEC131A

Resistance

: 3.3 - 4.0 

Ω [at 25°C (77°F)]

Continuity should not exist.

SEF220W

EC-420

[KA24DE]

DTC P1143 HO2S1

4. 

CHECK HEATED OXYGEN SENSOR 1

Refer to 

EC-207, "Component Inspection"

 .

OK or NG

OK

>> GO TO 6.

NG

>> Replace heated oxygen sensor 1.

5. 

CHECK INTERMITTENT INCIDENT

Perform 

EC-120, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

Refer to 

EC-205, "Wiring Diagram"

 , for circuit.

>> INSPECTION END.

Removal and Installation

UBS00D9U

HEATED OXYGEN SENSOR 1

Refer to

EM-13, "OUTER COMPONENT PARTS"

 .

DTC P1144 HO2S1

EC-421

[KA24DE]

C

D

E

F

G

H

I

J

K

L

M

A

EC

DTC P1144 HO2S1

PFP:22690

Component Description

UBS00D9V

The heated oxygen sensor 1 is placed into the exhaust manifold. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 has a closed-end tube
made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions. The
heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts
the injection pulse duration to achieve the ideal air-fuel ratio. The
ideal air-fuel ratio occurs near the radical change from 1V to 0V.

CONSULT-II Reference Value in Data Monitor Mode

UBS00D9W

Specification data are reference values.

On Board Diagnosis Logic

UBS00D9X

To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the “rich” output is sufficiently
high. The “lean” output is sufficiently low. When both the outputs are
shifting to the rich side, the malfunction will be detected.

SEF463R

SEF288D

 MONITOR ITEM

CONDITION

SPECIFICATION

HO2S1 (B1)

●

Engine: After warming up

Maintaining engine speed at 2,000 
rpm

0 - 0.3V 

←→ Approx. 0.6 - 1.0V

HO2S1 MNTR (B1)

LEAN 

←→ RICH

Changes more than 5 times during 
10 seconds.

SEF299U

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1144

Heated oxygen sensor 
1 rich shift monitoring

The maximum and minimum voltages from the 
sensor are beyond the specified voltages.

●

Heated oxygen sensor 1

●

Heated oxygen sensor 1 heater

●

Fuel pressure

●

Fuel injector

EC-422

[KA24DE]

DTC P1144 HO2S1

DTC Confirmation Procedure

UBS00D9Y

CAUTION:

Always drive vehicle at a safe speed.

NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch OFF and wait at
least 5 seconds before conducting the next test.
TESTING CONDITION:

●

Always perform at a temperature above 

−10°C (14°F).

●

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

 WITH CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Stop engine and wait at least 5 seconds.

3.

Turn ignition switch ON and select “HO2S1 (B1) P1144” of “HO2S1” in “DTC WORK SUPPORT” mode
with CONSULT-II.

4.

Touch “START”.

5.

Start engine and let it idle for at least 3 minutes.

NOTE:
Never raise engine speed above 3,600 rpm after this step. If
the engine speed limit is exceeded, return to step 5.

6.

When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen. Maintain the conditions con-
tinuously until “TESTING” changes to “COMPLETED”. (It will
take approximately 50 seconds or more.)

If “TESTING” is not displayed after 5 minutes, retry from
step 2.

7.

Make sure that “OK” is displayed after touching “SELF-DIAG
RESULTS”. If “NG” is displayed, refer to 

EC-423, "Diagnostic

Procedure"

 .

Overall Function Check

UBS00D9Z

Use this procedure to check the overall function of the front heated oxygen sensor circuit. During this check, a
DTC might not be confirmed.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

LEC056A

ENG SPEED

1,200 - 3,150 rpm

Vehicle speed

Less than 100 km/h (Less than 62 MPH)

B/FUEL SCHDL

3.5 - 15 msec 

Selector lever

Suitable position

LEC057A

LEC058A