Infiniti M45 (Y34). Manual - part 446

DTC P1143, P1163 HO2S1

EC-473

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EC

 Without CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

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

3.

Check the following with engine speed held at 2,000 rpm con-
stant under no load.

●

The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V
more than 5 times within 10 seconds.

●

The maximum voltage is over 0.6V at least 1 time.

●

The minimum voltage is below 0.3V at least 1 time.

●

The voltage never exceeds 1.0V.

1 time: 0 - 0.3V 

→

 0.6 - 1.0V 

→

 0 - 0.3V

2 times: 0 - 0.3V 

→

 0.6 - 1.0V 

→

 0 - 0.3V 

→

 0.6 - 1.0V 

→

 0 -

0.3V

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.

●

Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.

Removal and Installation

ABS002OG

HEATED OXYGEN SENSOR 1

Refer to 

EM-22, "EXHAUST MANIFOLD AND THREE WAY CATALYST"

 .

PBIB0063E

EC-474

DTC P1144, P1164 HO2S1

DTC P1144, P1164 HO2S1

PFP:22690

Component Description

ABS002OH

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

ABS002OI

Specification data are reference values.

On Board Diagnosis Logic

ABS002OJ

To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the rich output is sufficiently
high, and 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)
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

●

Fuel injector

P1164
1164
(Bank 2)

DTC P1144, P1164 HO2S1

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DTC Confirmation Procedure

ABS002OK

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:

●

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” 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 3,000 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 more than 40 seconds.)

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-476, "Diagnostic

Procedure"

 .

PBIB0548E

ENG SPEED

1,100 - 2,000 rpm

VHCL SPEED SE

Less than 100 km/h (62 MPH)

B/FUEL SCHDL

1.6 - 12.0 msec

Selector lever

Suitable position

PBIB0549E

SEC772C

EC-476

DTC P1144, P1164 HO2S1

Overall Function Check

ABS002OL

Use this procedure to check the overall function of the heated oxygen sensor 1 circuit. During this check, a 1st
trip 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 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-476, "Diagnostic Procedure"

 .

Diagnostic Procedure

ABS002OM

1. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws. 
Refer to 

EC-141, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace ground connections.

2. 

RETIGHTEN HEATED OXYGEN SENSOR 1

Loosen and retighten heated oxygen sensor 1.

>> GO TO 3.

PBIB0063E

PBIB1118E

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

PBIB0016E