Infiniti F50. Manual - part 457

DTC P1144, P1164 HO2S1

EC-469

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EC

DTC P1144, P1164 HO2S1

PFP:22690

Component Description

EBS00MIO

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 1 to 0V.

CONSULT-II Reference Value in Data Monitor Mode

EBS00MIP

Specification data are reference values.

On Board Diagnosis Logic

EBS00MIQ

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

SEF463R

SEF288D

MONITOR ITEM

CONDITION

SPECIFICATION

HO2S1 (B1)
HO2S1 (B2)

●

Engine: After warming up

Maintaining engine speed at 2,000 rpm

0 - 0.3V 

←→

 Approx. 0.6 - 1.0V

HO2S1 MNTR (B1)
HO2S1 MNTR (B2)

●

Engine: After warming up

Maintaining engine speed at 2,000 rpm

LEAN 

←→

 RICH

Changes more than 5 times during 
10 seconds.

SEF299U

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1144
1144
(Bank 1)

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

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Injectors

P1164
1164
(Bank 2)

EC-470

DTC P1144, P1164 HO2S1

DTC Confirmation Procedure

EBS00MIR

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 10 seconds before conducting the next test.

TESTING CONDITION:

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Always perform at a temperature above 

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10

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C (14

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F).

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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” or “HO2S1 (B2) P1164” 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 40 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-471, "Diagnostic

Procedure"

 .

PBIB0548E

ENG SPEED

1,100 - 2,000 rpm

Vehicle speed

Less than 100 km/h (62 MPH)

B/FUEL SCHDL

1.6 - 12.0 msec

Selector lever

Suitable position

PBIB0549E

SEC772C

DTC P1144, P1164 HO2S1

EC-471

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Overall Function Check

EBS00MIS

Use this procedure to check the overall function of the heated oxygen sensor 1 circuit. During this check, a
DTC might not be confirmed.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Set voltmeter probes between ECM terminal 114 [HO2S1(B1) signal] 115 [HO2S1(B2) signal] and engine
ground.

3.

Check one of the following with engine speed held at 2,000 rpm
constant under no load.

–

The maximum voltage is below 0.8V at least 1 time.

–

The minimum voltage is below 0.35V at least 1 time.

4.

If NG, go to 

EC-471, "Diagnostic Procedure"

 .

Diagnostic Procedure

EBS00MIT

1. 

RETIGHTEN GROUND SCREWS

1.

Turn ignition switch “OFF”.

2.

Loosen and retighten engine ground screws.

>> GO TO 2.

2. 

RETIGHTEN HEATED OXYGEN SENSOR 1

Loosen and retighten heated oxygen sensor 1.

>> GO TO 3.

PBIB0063E

PBIB0011E

Tightening torque: 40 - 50 N·m (4.1 - 5.1 kg-m, 30 - 37 ft-lb)

PBIB0016E

EC-472

DTC P1144, P1164 HO2S1

3. 

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 P0172 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 5 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-63, "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 P0172 detected?
Is it difficult to start engine?

Yes or No

Yes

>> Perform trouble diagnosis for DTC P0172. Refer to 

EC-274

 .

No

>> GO TO 4.

SEF968Y

PBIB0012E