2004 INFINITI FX35 Engine

EC-232
[VQ35DE]
DTC P0134, P0154 HO2S1
Revision: 2004 November 2004 FX35/FX45
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureABS006OE
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-141, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
16 R/LHeated oxygen sensor 1
(bank 2)[Engine is running]

Warm-up condition

Engine speed is 2,000 rpm0 - Approximately 1.0V
(Periodically change)
78 B/RSensor ground
(Heated oxygen sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
PBIB2195E

EC-234
[VQ35DE]
DTC P0134, P0154 HO2S1
Revision: 2004 November 2004 FX35/FX45
4. CHECK HEATED OXYGEN SENSOR 1
Refer to EC-234, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace malfunctioning heated oxygen sensor 1.
5. CHECK INTERMITTENT INCIDENT
Refer to EC-135, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionABS006OF
HEATED OXYGEN SENSOR 1
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “MANU TRIG” and adjust “TRIGGER POINT” to 100% in “DATA MONITOR” mode with CONSULT-
II.
3. Select “HO2S1 (B1)/(B2)” and “HO2S1 MNTR (B1)/(B2)”.
4. Hold engine speed at 2,000 rpm under no load during the following steps.
5. Touch “RECORD” on CONSULT-II screen.
6. Check the following.

“HO2S1 MNTR (B1)/(B2)” in “DATA MONITOR” mode
changes from “RICH” to “LEAN” to “RICH” 5 times in 10 sec-
onds.
5 times (cycles) are counted as shown at right.

“HO2S1 (B1)/(B2)” voltage goes above 0.6V at least once.

“HO2S1 (B1)/(B2)” voltage goes below 0.3V at least once.

“HO2S1 (B1)/(B2)” voltage never exceeds 1.0V.
SEF646Y
SEF647Y
SEF648Y

DTC P0134, P0154 HO2S1
EC-235
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2004 November 2004 FX35/FX45
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.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 35 [HO2S1 (B1) signal] or 16 [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 one time.

The minimum voltage is below 0.3V at least one 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
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 InstallationABS006OG
HEATED OXYGEN SENSOR 1
Refer to EM-26, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
PBIB1107E

EC-236
[VQ35DE]
DTC P0138, P0158 HO2S2
Revision: 2004 November 2004 FX35/FX45
DTC P0138, P0158 HO2S2PFP:226A0
Component DescriptionABS006OH
The heated oxygen sensor 2, after three way catalyst 1, monitors the
oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the heated oxygen sensor 1 are
shifted, the air-fuel ratio is controlled to stoichiometric, by the signal
from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor ModeABS006OI
Specification data are reference values.
On Board Diagnosis LogicABS006OJ
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the heated oxygen sensor 1. The oxygen
storage capacity of the three way catalyst 1 causes the longer
switching time. To judge the malfunctions of heated oxygen sensor
2, ECM monitors whether the voltage is unusually high during the
various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.Revving engine from idle to 3,000 rpm
quickly.0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)LEAN ←→ RICH
SEF305UA
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0138
0138
(Bank 1)
Heated oxygen sensor
2 circuit high voltageAn excessively high voltage from the sensor is
sent to ECM.

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

Heated oxygen sensor 2 P0158
0158
(Bank 2)

DTC P0138, P0158 HO2S2
EC-237
[VQ35DE]
C
D
E
F
G
H
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K
L
MA
EC
Revision: 2004 November 2004 FX35/FX45
DTC Confirmation ProcedureABS006OK
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.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 2 minutes.
6. If 1st trip DTC is detected, go to EC-137, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF174Y

DTC P0138, P0158 HO2S2
EC-239
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2004 November 2004 FX35/FX45
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
74 LG/BHeated oxygen sensor 2
(bank 1)[Engine is running]

Warm-up condition

Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load0 - Approximately 1.0V
78 B/RSensor ground
(Heated oxygen sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V

DTC P0138, P0158 HO2S2
EC-241
[VQ35DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2004 November 2004 FX35/FX45
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
Diagnostic ProcedureABS00CH2
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-141, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between HO2S2 terminal 4 and ECM
terminal 78.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to ground
or short to power in harness or connectors.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
55 W/RHeated oxygen sensor 2
(bank 2)[Engine is running]

Warm-up condition

Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load0 - Approximately 1.0V
78 B/RSensor ground
(Heated oxygen sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
PBIB2195E
Continuity should exist.
PBIB1576E

DTC P0138, P0158 HO2S2
EC-243
[VQ35DE]
C
D
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H
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MA
EC
Revision: 2004 November 2004 FX35/FX45
Component InspectionABS006ON
HEATED OXYGEN SENSOR 2
With CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and
4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Select “FUEL INJECTION” in “ACTIVE TEST” mode, and select
“HO2S2 (B1)/(B2)” as the monitor item with CONSULT-II.
7. Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)/(B2)” should be above 0.63V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.48V at least once when the “FUEL INJECTION” is −25%.
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.
Without CONSULT-II
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Set voltmeter probes between ECM terminal 74 [HO2S2 (B1) signal] or 55 [HO2S2 (B2) signal] and
ground.
SEF174Y
SEF662Y
PBIB0796E