heater INFINITI QX4 2005 Factory Workshop Manual

EC-142Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
IGNITION SW
Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW

Engine: After warming up, idle
the engineHeater fan: Not operating OFF
Heater fan: Operating ON
BRAKE SW

Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 10° - 20° BTDC
2,000 rpm 25° - 45° BTDC
CAL/LD VALUE

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V

Engine: After warming up

Selector lever: P or N

Air conditioner switch: OFF

No loadIdle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)0%
2,000 rpm —
AIR COND RLY

Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor: Operates)ON
FUEL PUMP RLY

For 1 second after turning ignition switch ON

Engine running or crankingON

Except above conditions OFF
VENT CONT/V

Ignition switch: ON OFF
THRTL RELAY

Ignition switch: ON ON
COOLING FAN

Engine: After warming up, idle
the engine

Air conditioner switch: OFFEngine coolant temperature: 99°C
(210°F) or lessOFF
Engine coolant temperature: 100°C
(212°F) or moreHI
HO2S2 HTR (B1)
HO2S2 HTR (B2)

Engine speed is 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
I/P PULLY SPD

Vehicle speed: More than 20 km/h (12 MPH)Almost the same speed as the
tachometer indication
VEHICLE SPEED

Turn drive wheels and compare CONSULT-II value with the speedometer
indication.Almost the same speed as the
speedometer indication
TRVL AFTER MIL

Ignition switch: ONVehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,723 mile) MONITOR ITEM CONDITION SPECIFICATION

EC-166Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
DTC P0037, P0038, P0057, P0058 HO2S2 HEATERPFP:226A0
DescriptionUBS00H0N
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 ModeUBS00H0O
Specification data are reference values.
On Board Diagnosis LogicUBS00H0P
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 is 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 name DTC 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.)

Heater 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.)

Heater oxygen sensor 2 heater P0058
0058
(Bank 2)

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-167
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Revision: October 20052005 QX56
DTC Confirmation ProcedureUBS00H0Q
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 10.5V 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-171, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF 1 74 Y

EC-168Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
Wiring DiagramUBS00H0R
BANK 1
BBWA1672E

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-169
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Revision: October 20052005 QX56
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)
6GRHeated oxygen sensor 2
heater (bank 1)[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpm after the
following conditions are met.
–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)

EC-170Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
BANK 2
BBWA1673E

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-171
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Revision: October 20052005 QX56
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 ProcedureUBS00H0S
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-162, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
25 O/GHeated oxygen sensor 2
heater (bank 2)[Engine is running]

Warm-up condition

Engine speed is below 3,600 rpm after the
following conditions are met.
–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)
BBIA0354E

EC-172Revision: October 2005
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2005 QX56
2. CHECK HO2S2 POWER SUPPLY CIRCUIT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Turn ignition switch ON.
3. Check voltage between HO2S2 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 E5, F14

IPDM E/R connector E119

10A fuse

Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair harness or connectors.
4. CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal and HO2S2 terminal as follows.
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.
BBIA0435E
Voltage: Battery voltage
PBIB0 112 E
DTCTe r m i n a l s
Bank
ECM Sensor
P0037, P0038 6 2 1
P0057, P0058 25 2 2
Continuity should exist.

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-173
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Revision: October 20052005 QX56
5. CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-173, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-156, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00H0T
HEATED OXYGEN SENSOR 2 HEATER
1. Check resistance between HO2S2 terminals as follows.
2. If NG, replace heated oxygen sensor 2.
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 sur-
face 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 InstallationUBS00H0U
HEATED OXYGEN SENSOR 2
Refer to EM-19, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
Terminal No. Resistance
2 and 3 5.0 - 7.0 Ω at 25°C (77°F)
1 and 2, 3, 4
∞ Ω
(Continuity should not exist)
4 and 1, 2, 3
SEF 2 49 Y

DTC P0300 - P0308 MULTIPLE CYLINDER MISFIRE, NO. 1 - 8 CYLINDER MIS-
FIRE
EC-277
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Revision: October 20052005 QX56
13. CHECK A/F SENSOR 1 INPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect A/F sensor 1 harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Check harness continuity between the following terminals and ground.
Refer to Wiring Diagram.
6. Also check harness for short to power.
OK or NG
OK >> GO TO 14.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
14. CHECK A/F SENSOR 1 HEATER
Refer to EC-392, "
Component Inspection" .
OK or NG
OK >> GO TO 15.
NG >> Replace (malfunctioning) A/F sensor 1.
A/F sensor 1 terminal ECM terminal
Bank 1116
275
535
656
Bank 2176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal
116176
275277
535557
656658
Continuity should not exist.
BBIA0376E