2007 INFINITI M35 heater

EC-174
[VQ35DE]
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
Revision: 2007 April2007 M35/M45
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureNBS004U5
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body.
Refer to EC-160, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
24 OA/F sensor 1 heater
(bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 5V
57 GR/L
A/F sensor 1 (bank 2)[Engine is running]

Warm-up condition

Idle speedApproximately 2.6V
58 LG/BApproximately 2.3V
76 W/LApproximately 3.1V
77 YApproximately 2.3V
PBIB1584E
1. Body ground M70 2. Body ground M16
PBIB2782E

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-175
[VQ35DE]
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Revision: 2007 April2007 M35/M45
2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors E12, F3

IPDM E/R harness connector E7

15A fuse

Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
4. CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following;
ECM terminal 2 and A/F sensor 1 (bank 1) terminal 4 or
ECM terminal 24 and A/F sensor 1 (bank 2) terminal 4.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.Voltage: Battery voltage
PBIB2794E
PBIB1683E
Continuity should exist.

EC-176
[VQ35DE]
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
Revision: 2007 April2007 M35/M45
5. CHECK A/F SENSOR 1 HEATER
Refer to EC-176, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning air fuel ratio (A/F) sensor 1.
6. CHECK INTERMITTENT INCIDENT
Perform EC-153, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionNBS004U6
AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Check resistance between terminals 3 and 4.
Check continuity between terminals 3 and 1, 2, 5, 6, terminals 4 and
1, 2, 5, 6.
If NG, replace the air fuel ratio (A/F) sensor 1.
CAUTION:

Discard any air fuel ratio (A/F) 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 air fuel ratio (A/F) sensor, clean
exhaust system threads using Heated Oxygen Sensor
Thread Cleaner tool J-43897-18 or J-43897-12 and approved
anti-seize lubricant.
Removal and Installation NBS004U7
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-28, "EXHAUST MANIFOLD" . Resistance: 2.3 - 4.3Ω [at 25°C (77°F)]
Continuity should not exist.
PBIB1684E

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-177
[VQ35DE]
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Revision: 2007 April2007 M35/M45
DTC P0037, P0038, P0057, P0058 HO2S2 HEATERPFP:226A0
DescriptionNBS004U8
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 ModeNBS004U9
Specification data are reference values.
On Board Diagnosis LogicNBS004UA
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated 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 3,600OFF
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 loadON
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 loadON

Engine speed: Above 3,600 rpm OFF
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0037
0037
(Bank 1)Heated oxygen
sensor 2 heater
control circuit lowThe 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
(The 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 highThe 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
(The heated oxygen sensor 2 heater circuit is
shorted.)

Heated oxygen sensor 2 heater P0058
0058
(Bank 2)

EC-178
[VQ35DE]
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
Revision: 2007 April2007 M35/M45
DTC Confirmation ProcedureNBS004UB
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:
Before performing the following procedure, confirm that battery voltage is between 11V and 16V at
idle.
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 the engine and keep the engine speed between 3,500 rpm
and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. If 1st trip DTC is detected, go to EC-182, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF174Y

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-179
[VQ35DE]
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Revision: 2007 April2007 M35/M45
Wiring DiagramNBS004UC
BANK 1
TBWT1470E

EC-180
[VQ35DE]
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
Revision: 2007 April2007 M35/M45
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)
25 P/BHeated oxygen sensor 2
heater (bank 1)[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 load0 - 1.0V
[Ignition switch: ON]

Engine stopped
[Engine is running]

Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
74 WHeated oxygen sensor 2
(bank 1)[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 load0 - Approximately 1.0V
78 BSensor ground
(Heated oxygen sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-181
[VQ35DE]
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Revision: 2007 April2007 M35/M45
BANK 2
TBWT1471E