2007 INFINITI FX35 air condition

EC-172
[VQ35DE]
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
Revision: 2006 July 2007 FX35/FX45
DTC P0037, P0038, P0057, P0058 HO2S2 HEATERPFP:226A0
DescriptionNBS003MV
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeNBS003MW
Specification data are reference values.
On Board Diagnosis LogicNBS003MX
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Heated oxygen sensor 2
heater control Heated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600 OFF
Below 3,600 rpm after the following conditions are met.

Engine: After warming up

Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no load ON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)

Engine speed: Below 3,600 rpm after the following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no load ON

Engine speed: Above 3,600 rpm OFF
DTC No.
Trouble diagnosis
name DTC detecting condition Possible cause
P0037
0037
(Bank 1) Heated oxygen
sensor 2 heater
control circuit low The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)

Harness or connectors
(Heated oxygen sensor 2 heater circuit is
open or shorted.)

Heated oxygen sensor 2 heater
P0057
0057
(Bank 2)
P0038
0038
(Bank 1) Heated oxygen
sensor 2 heater
control circuit high The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to
ECM through the heated oxygen sensor 2
heater.)

Harness or connectors
(Heated oxygen sensor 2 heater circuit is
shorted.)

Heated oxygen sensor 2 heater
P0058
0058
(Bank 2)

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER EC-177
[VQ35DE]
C
D E
F
G H
I
J
K L
M A
EC
Revision: 2006 July 2007 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 ProcedureNBS003N0
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body. Refer to EC-153, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
6R Heated oxygen sensor 2
heater (bank 2) [Engine is running]

Engine speed: Below 3,600 rpm after the
following conditions are met.
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load 0 - 1.0V
[Ignition switch: ON]

Engine stopped
[Engine is running]

Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
55 W/R Heated oxygen sensor 2
(bank 2) [Engine is running]

Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–Engine: After warming up
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load 0 - Approximately 1.0V
78 B/R Sensor ground
(Heated oxygen sensor) [Engine is running]

Warm-up condition

Idle speed
Approximately 0V
PBIB2625E

EC-180
[VQ35DE]
DTC P0075, P0081 IVT CONTROL SOLENOID VALVE
Revision: 2006 July 2007 FX35/FX45
DTC P0075, P0081 IVT CONTROL SOLENOID VALVEPFP:23796
Component DescriptionNBS003TN
Intake valve timing control solenoid valve is activated by ON/OFF
pulse duty (ratio) signals from the ECM.
The intake valve timing control solenoid valve changes the oil
amount and direction of flow through intake valve timing control unit
or stops oil flow.
The longer pulse width advances valve angle.
The shorter pulse width retards valve angle.
When ON and OFF pulse widths become equal, the solenoid valve
stops oil pressure flow to fix the intake valve angle at the control
position.
CONSULT-II Reference Value in Data Monitor ModeNBS003TO
Specification data are reference values.
On Board Diagnosis LogicNBS003TP
DTC Confirmation ProcedureNBS003TQ
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.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If 1st trip DTC is detected, go to EC-185, "
Diagnostic Procedure"
.
WITH GST
Following the procedure “WITH CONSULT-II” above.
PBIB1842E
MONITOR ITEM CONDITION SPECIFICATION
INT/V SOL(B1)
INT/V SOL(B2)

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle 0% - 2%
When revving engine up to 2,000 rpm
quickly Approx. 0% - 50%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0075
0075
(Bank 1) Intake valve timing control
solenoid valve circuit An improper voltage is sent to the ECM
through intake valve timing control solenoid
valve.

Harness or connectors
(Intake valve timing control solenoid valve
circuit is open or shorted.)

Intake valve timing control solenoid valve
P0081
0081
(Bank 2)
SEF058Y

DTC P0101 MAF SENSOR EC-187
[VQ35DE]
C
D E
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G H
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K L
M A
EC
Revision: 2006 July 2007 FX35/FX45
DTC P0101 MAF SENSORPFP:22680
Component DescriptionNBS003N3
The mass air flow (MAF) sensor is placed in the stream of intake air.
It measures the intake flow rate by measuring a part of the entire
intake flow. The mass air flow sensor controls the temperature of the
hot wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current supplied to hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor ModeNBS003N4
Specification data are reference values.
On Board Diagnosis LogicNBS003N5
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-137, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle 5% - 35%
2,500 rpm 5% - 35%
MASS AIRFLOW

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0101
0101 Mass air flow sensor cir-
cuit range/performance A)
A high voltage from the sensor is sent to ECM
under light load driving condition.

Harness or connectors
(Mass air flow sensor circuit is
open or shorted.)

Mass air flow sensor

EVAP control system pressure
sensor

Intake air temperature sensor
B) A low voltage from the sensor is sent to ECM
under heavy load driving condition.

Harness or connectors
(Mass air flow sensor circuit is
open or shorted.)

Intake air leaks

Mass air flow sensor

EVAP control system pressure
sensor

Intake air temperature sensor

DTC P0101 MAF SENSOR EC-189
[VQ35DE]
C
D E
F
G H
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K L
M A
EC
Revision: 2006 July 2007 FX35/FX45
7. Maintain the following conditions for at least 10 consecutive sec-
onds.
8. If 1st trip DTC is detected, go to EC-191, "
Diagnostic Procedure"
.
Overall Function CheckNBS003N7
PROCEDURE FOR MALFUNCTION B
Use this procedure to check the overall function of the mass air flow sensor 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. Select Service $01 with GST.
3. Check the mass air flow sensor signal with Service $01.
4. Check for linear mass air flow sensor signal value rise in response to increases to about 4,000 rpm in engine speed.
5. If NG, go to EC-191, "
Diagnostic Procedure" .
ENG SPEED More than 2,000 rpm
THRTL SEN 1 More than 3V
THRTL SEN 2 More than 3V
Selector lever Suitable position
Driving location Driving vehicle uphill (Increased engine load) will help
maintain the driving conditions required for this test.
PBIB0199E
SEF534P

DTC P0101 MAF SENSOR EC-191
[VQ35DE]
C
D E
F
G H
I
J
K L
M A
EC
Revision: 2006 July 2007 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 ProcedureNBS003N9
1. INSPECTION START
Which malfunction (A or B) is duplicated?
A or B
A>>GO TO 3.
B>>GO TO 2.
2. CHECK INTAKE SYSTEM
Check the following for connection.

Air duct

Va c u u m h o s e s

Intake air passage between air duct and intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
51 L/W Mass air flow sensor [Engine is running]

Warm-up condition

Idle speed
1.0 - 1.2V
[Engine is running]

Warm-up condition

Engine speed: 2,500 rpm 1.6 - 2.0V
67 B/W Sensor ground [Engine is running]

Warm-up condition

Idle speed Approximately 0V
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF 0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 9
120 R
R/B Power supply for ECM
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)

EC-194
[VQ35DE]
DTC P0101 MAF SENSOR
Revision: 2006 July 2007 FX35/FX45
Component InspectionNBS003NA
MASS AIR FLOW SENSOR
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-II and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the follow- ing conditions.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 4 again. If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.
Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
Condition MAS A/F SE-B1 (V)
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.) 1.0 - 1.2
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.6 - 2.0
Idle to about 4,000 rpm 1.0 - 1.2 to Approx. 2.4*
PBIB2371E
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.) 1.0 - 1.2
2,500 rpm (Engine is warmed-up to
normal operating temperature.) 1.6 - 2.0
Idle to about 4,000 rpm 1.0 - 1.2 to Approx. 2.4*
PBIB1106E

EC-196
[VQ35DE]
DTC P0102, P0103 MAF SENSOR
Revision: 2006 July 2007 FX35/FX45
DTC P0102, P0103 MAF SENSORPFP:22680
Component DescriptionNBS003NC
The mass air flow (MAF) sensor is placed in the stream of intake air.
It measures the intake flow rate by measuring a part of the entire
intake flow. The mass air flow sensor controls the temperature of the
hot wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, electric current is supplied to hot wire is changed to main-
tain the temperature of the hot wire as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor ModeNBS003ND
Specification data are reference values.
On Board Diagnosis LogicNBS003NE
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-137, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
CAL/LD VALUE

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle 5% - 35%
2,500 rpm 5% - 35%
MASS AIRFLOW

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No load Idle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No. Trouble diagnosis
name DTC detecting condition Possible cause
P0102
0102 Mass air flow sensor
circuit low input An excessively low voltage from the sensor is
sent to ECM.

Harness or connectors
(Mass air flow sensor circuit is open or
shorted.)

Intake air leaks

Mass air flow sensor
P0103
0103 Mass air flow sensor
circuit high input An excessively high voltage from the sensor is
sent to ECM.

Harness or connectors
(Mass air flow sensor circuit is open or
shorted.)

Mass air flow sensor
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.