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Infiniti Q45 (FY33). Manual - part 174

SEC033C

SEF354WA

COMPONENT INSPECTION

Heated oxygen sensor 2 (rear)

1) Start engine and drive vehicle at a speed of more than

70 km/h (43 MPH) for 2 consecutive minutes.

2) Stop vehicle with engine running.
3) Select “FUEL INJECTION” in “ACTIVE TEST” mode,

and select “HO2S2 (B1) (B2)” as the monitor item with
CONSULT-II.

4) Check “HO2S2 (B1) (B2)” at idle speed when adjusting

“FUEL INJECTION” to ±25%.
“HO2S2 (B1) (B2)” should be above 0.48V at least
once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1) (B2)” should be below 0.43V at least
once when the “FUEL INJECTION” is −25%.

------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ OR ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

1) Start engine and drive vehicle at a speed of more than

70 km/h (43 MPH) for 2 consecutive minutes.

2) Stop vehicle with engine running.
3) Set voltmeter probes between ECM terminals

(B2),

(B1) (sensor signal) and ground.

4) Check the voltage when racing up to 4,000 rpm under

no load at least 10 times.
(depress and release accelerator pedal as soon as pos-
sible)
The voltage should be above 0.48V at least once.
If the voltage is above 0.48V at step 4, step 5 is not
necessary.

5) Keep vehicle at idling for 10 minutes, then check the

voltage. Or check the voltage when coasting from 80
km/h (50 MPH) in D position with “OD” OFF.
The voltage should be below 0.43V at least once.

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 sys-
tem threads using Oxygen Sensor Thread Cleaner tool
J-43897-18 or J-43897-12 and approved anti-seize lubri-
cant.

SEF244Y

IDX

TROUBLE DIAGNOSIS FOR DTC P0138 (B1), P0158 (B2)

Heated Oxygen Sensor 2 (Rear) (P0138: Bank
1), (P0158: Bank 2) (Max. Voltage Monitoring)
(Cont’d)

EC-225

SEF327R

Heated Oxygen Sensor 2 (Rear) (P0139: Bank
1), (P0159: Bank 2) (Response Monitoring)

COMPONENT DESCRIPTION

The heated oxygen sensor 2 (rear), after three way catalyst, moni-
tors the oxygen level in the exhaust gas on left and right bank.
Even if switching characteristics of the heated oxygen sensor 1
(front) are shifted, the air fuel ratio is controlled to stoichiometric,
by the signal from the each heated oxygen sensor 2 (rear).
This sensor is made of ceramic zirconia. The zirconia generates
voltage from approximately 1V in richer conditions to 0V in leaner
conditions.
Under normal conditions the heated oxygen sensor 2 (rear) is not
used for engine control operation.

CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE

Specification data are reference values.

MONITOR ITEM

CONDITION

SPECIFICATION

HO2S2 (B1)
HO2S2 (B2)

Engine: After warming up

Revving engine from idle up to 2,000
rpm

0 - 0.3V

)

0.6 - 1.0V

HO2S2 MNTR (B1)
HO2S2 MNTR (B2)

LEAN

)

RICH

ECM TERMINALS AND REFERENCE VALUE

Specification data are reference values, and are measured between each terminal and ground.

CAUTION:

Do not use ECM ground terminals when measuring voltage. Doing so may result in damage to the
ECM’s transistor. Use a ground other than ECM terminals such as the body ground.

TER-

MINAL

NO.

WIRE

COLOR

ITEM

CONDITION

DATA

(DC voltage)

89 (B2)

Heated oxygen sensor 2
(rear)

Engine is running.

After warming up to normal operating tempera-
ture and revving engine from idle up to 2,000
rpm.

0 - Approximately 1.0V

90 (B1)

SEF302U

ON BOARD DIAGNOSIS LOGIC

The heated oxygen sensor 2 (rear) has a much longer switching
time between rich and lean than the heated oxygen sensor 1
(front). The oxygen storage capacity before the three way catalyst
causes the longer switching time. To judge the malfunctions of
heated oxygen sensor 2 (rear), ECM monitors whether the switch-
ing response of the sensor’s voltage is faster than specified during
the various driving condition such as fuel-cut.

TROUBLE DIAGNOSIS FOR DTC P0139 (B1), P0159 (B2)

EC-226

Diagnostic Trouble

Code No.

Malfunction is detected when ...

Check Items

(Possible Cause)

P0139
0707
(Bank 1)

It takes more time for the sensor to respond between rich and lean
than the specified time.

Harness or connectors
(The sensor circuit is open or shorted.)

Heated oxygen sensor 2 (rear)

Fuel pressure

Injectors

Intake air leaks

P0159
0708
(Bank 2)

SEC038C

SEC039C

SEC040C

SEC041C

DIAGNOSTIC TROUBLE CODE CONFIRMATION
PROCEDURE

CAUTION:

Always drive vehicle at a safe speed.
NOTE:

“COMPLETED” will appear on CONSULT-II screen when all
tests “COND1”, “COND2” and “COND3” are completed.

If “DIAGNOSTIC TROUBLE CODE CONFIRMATION PRO-
CEDURE” has been previously conducted, always turn
ignition switch “OFF” and wait at least 5 seconds before
conducting the next test.

TESTING CONDITION:
Never stop engine during this test. If the engine is stopped,
reperform this test from step 2).

Procedure for COND1
1) Start engine and warm it up to normal operating tem-

perature.

2) Turn ignition switch “OFF” and wait at least 5 seconds.
3) Turn ignition switch “ON” and select “HO2S2 (B1)

P0139, (B2) P0159” of “HO2S2” in “DTC WORK SUP-
PORT” mode with CONSULT-II.

4) Touch “START”.
5) Start engine (TCS switch “OFF”) and let it idle for at

least 30 seconds.

6) Rev engine up to 2,000 rpm 2 or 3 times quickly under

no load.
If “COMPLETED” appears on CONSULT-II screen, go
to the following step.

7) Drive vehicle at a speed of more than 70 km/h (43 MPH)

for 2 consecutive minutes.

8) When the following conditions are met, “TESTING” will

be displayed at “COND1” on the CONSULT-II screen.
Maintain the conditions continuously until “TESTING”
changes to “COMPLETED”. (It will take approximately
60 seconds.)
CMPS-RPM (POS): 1,200 - 2,500 rpm
Vehicle speed: 64 - 100 km/h (40 - 62 MPH)
B/FUEL SCHDL: 0.5 - 5.0 msec
Selector lever: Suitable position

NOTE:

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

If “COMPLETED” already appears at “COND2” on
CONSULT-II screen before “Procedure for COND2”
is conducted, it is unnecessary to conduct step 9).

IDX

TROUBLE DIAGNOSIS FOR DTC P0139 (B1), P0159 (B2)

Heated Oxygen Sensor 2 (Rear) (P0139: Bank
1), (P0159: Bank 2) (Response Monitoring)
(Cont’d)

EC-227

SEF668Y

Procedure for COND2
9) While driving, release accelerator pedal completely with

“OD” OFF from the above condition [step 8)] until
“INCOMPLETE” at “COND2” on CONSULT-II screen
has turned to “COMPLETED”. (It will take approximately
4 seconds.)

NOTE:

If “COMPLETED” already appears at “COND3” on
CONSULT-II screen before “Procedure for COND3”
is conducted, it is unnecessary to conduct step 10).

Procedure for COND3
10) Stop vehicle and let it idle until “INCOMPLETE” of

“COND3” on CONSULT-II screen has turned to “COM-
PLETED”. (It will take a maximum of approximately 6
minutes.)

11) Make sure that “OK” is displayed after touching “SELF-

DIAG RESULTS”.
If

“NG”

displayed,

refer

“DIAGNOSTIC

PROCEDURE”, EC-231.

SEF354WA

OVERALL FUNCTION CHECK

Use this procedure to check the overall function of the heated oxy-
gen sensor 2 (rear) circuit. During this check, a 1st trip DTC might
not be confirmed.

1) Start engine and drive vehicle at a speed of more than

70 km/h (43 MPH) for 2 consecutive minutes.

2) Stop vehicle with engine running.
3) Set voltmeter probes between ECM terminals

(B2),

(B1) (sensor signal) and ground.

4) Check the voltage when racing up to 4,000 rpm under

no load at least 10 times.
(depress and release accelerator pedal as soon as pos-
sible)
The voltage should be changed at more than 0.06V
for 1 second during this procedure.
If the voltage can be confirmed in step 4, step 5 is
not necessary.

5) Keep vehicle at idling for 10 minutes, then check the

voltage. Or check the voltage when coasting from 80
km/h (50 MPH) in D position with “OD” OFF.
The voltage should be changed at more than 0.06V
for 1 second during this procedure.

6) If NG, go to “DIAGNOSTIC PROCEDURE”, EC-231.

TROUBLE DIAGNOSIS FOR DTC P0139 (B1), P0159 (B2)

Heated Oxygen Sensor 2 (Rear) (P0139: Bank
1), (P0159: Bank 2) (Response Monitoring)
(Cont’d)

EC-228

Content .. 172 173 174 175 ..