2004 INFINITI QX56 Combination

DI-56
WARNING CHIME
Revision: August 20072004 QX56
5. CHECK KEY SWITCH CIRCUIT
1. Disconnect BCM connector.
2. Check continuity between BCM harness connector M18 terminal
37 (B/R) and key switch and key lock solenoid harness connec-
tor M27 terminal 4 (B/R).
3. Check continuity between BCM harness connector M18 terminal
37 (B/R) and ground.
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.
6. CHECK KEY SWITCH POWER SUPPLY CIRCUIT
Check voltage between key switch and key lock solenoid harness
connector M27 terminal 3 (Y/R) and ground.
OK or NG
OK >> Replace the BCM. Refer to BCS-19, "Removal and
Installation of BCM" .
NG >> Check harness for open or short between fuse and key
switch and key lock solenoid.
Light Warning Chime Does Not OperateEKS007EQ
1. CHECK WARNING CHIME OPERATION
Check key warning chime and seat belt warning chime functions.
Do key warning chime and seat belt warning chime sound?
YES >> GO TO 2.
NO >> Go to DI-53, "
All Warning Chimes Do Not Operate" .
2. CHECK BCM INPUT SIGNAL
With CONSULT-II
1. Select "BCM".
2. With "DATA MONITOR" of "BUZZER", confirm "LIGHT SW 1ST"
status changes when the lighting switch is moved from ON (1st
position) to OFF.
Without CONSULT-II
Check combination switch. Refer to LT-98, "
Combination Switch
Reading Function" .
OK or NG
OK >> Replace the BCM. Refer to BCS-19, "Removal and Installation of BCM" .
NG >> Check lighting switch. Refer to LT-98, "
Combination Switch Reading Function" . Continuity should exist.
Continuity should not exist.
WKIA2074E
Battery voltage should exist.
WKIA2075E
Lighting switch ON (1st position) : LIGHT SW 1ST ON
Lighting switch OFF : LIGHT SW 1ST OFF
WKIA1877E

WARNING CHIME
DI-57
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DI
Revision: August 20072004 QX56
Seat Belt Warning Chime Does Not OperateEKS007ER
1. CHECK WARNING CHIME OPERATION
1. With key removed from the ignition and the front door LH open, turn the lighting switch to 1st or 2nd posi-
tion.
2. Return lighting switch to OFF position, and insert key into ignition.
Does warning chime sound for both steps?
YES >> GO TO 2.
NO >> Go to DI-53, "
All Warning Chimes Do Not Operate" .
2. CHECK SEAT BELT WARNING LAMP OPERATION
Turn ignition switch ON. Buckle and unbuckle the driver seat belt while watching seat belt warning lamp.
OK or NG
OK >> Replace the BCM. Refer to BCS-19, "Removal and Installation of BCM" .
NG >> GO TO 3.
3. CHECK COMBINATION METER INPUT SIGNAL
1. Turn ignition switch ON.
2. Check voltage between combination meter harness connector
M24 terminal 27 (O/B) and ground.
OK or NG
OK >> Replace the combination meter. Refer to DI-25, "Removal and Installation of Combination Meter"
NG >> GO TO 4.
4. CHECK SEAT BELT BUCKLE SWITCH
1. Turn ignition switch OFF.
2. Disconnect seat belt buckle pre-tensioner assembly LH (seat
belt buckle switch) connector.
3. Check continuity between seat belt buckle pre-tensioner assem-
bly LH (seat belt buckle switch) terminals 1 and 2.
OK or NG
OK >> GO TO 5.
NG >> Replace the seat belt buckle pre-tensioner assembly LH (seat belt buckle switch).When seat belt is fastened : Warning lamp OFF
When seat belt is unfastened : Warning lamp ON
Te r m i n a l s
ConditionVoltage (V)
(Approx.) (+)
(–)
ConnectorTe r m i n a l
(Wire
color)
M24 27 (O/B) GroundSeat belt is fastened Battery voltage
Seat belt is unfastened 0
WKIA1821E
Terminals Condition Continuity
12Seat belt is fastened No
Seat belt is unfastened Yes
WKIA4163E

DI-58
WARNING CHIME
Revision: August 20072004 QX56
5. CHECK SEAT BELT BUCKLE SWITCH CIRCUIT
1. Disconnect combination meter connector.
2. Check continuity between combination meter harness connector
M24 terminal 27 (O/B) and seat belt buckle pre-tensioner
assembly LH (seat belt buckle switch) harness connector B74
terminal 1 (O/B).
3. Check continuity between combination meter harness connector M24 terminal 27 (O/B) and ground.
OK or NG
OK >> Check seat belt buckle pre-tensioner assembly LH (seat belt buckle switch) ground circuit.
NG >> Repair harness or connector.
AB
Continuity
Connector Terminal Connector Terminal
Combina-
tion meter:
M2427Seat belt
buckle pre-
tensioner
assembly LH
(seat belt
buckle
switch): B741Yes
B
GroundContinuity
Connector Terminal
Combina-
tion meter:
M2427 No
WKIA4164E

EC-108Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
A/F ALPHA-B1 [%]×

The mean value of the air-fuel ratio feedback
correction factor per cycle is indicated.

When the engine is stopped, a certain
value is indicated.

This data also includes the data for the
air-fuel ratio learning control. A/F ALPHA-B2 [%]×
COOLAN TEMP/S
[°C] or [°F]××

The engine coolant temperature (determined
by the signal voltage of the engine coolant
temperature sensor) is displayed.

When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine
coolant temperature determined by the
ECM is displayed.
A/F SEN1 (B1) [V]××

The A/F signal computed from the input signal
of the A/F sensor 1 is displayed.
A/F SEN1 (B2) [V]×
HO2S2 (B1) [V]×

The signal voltage of the heated oxygen sen-
sor 2 is displayed.
HO2S2 (B2) [V]×
HO2S2 MNTR (B1)
[RICH/LEAN]×

Display of heated oxygen sensor 2 signal:
RICH: Means the amount of oxygen after
three way catalyst is relatively small.
LEAN: Means the amount of oxygen after
three way catalyst is relatively large.

When the engine is stopped, a certain
value is indicated.
HO2S2 MNTR (B2)
[RICH/LEAN]×
VHCL SPEED SE
[km/h] or [mph]××

The vehicle speed computed from the vehicle
speed signal sent from combination meter is
displayed.
BATTERY VOLT
[V]××

The power supply voltage of ECM is dis-
played.
ACCEL SEN 1 [V]××

The accelerator pedal position sensor signal
voltage is displayed.
ACCEL SEN 2 [V]×
Accelerator pedal position sensor 2
signal is converted by ECM internally.
Thus, it differs from ECM terminal volt-
age signal.
THRTL SEN 1 [V]××

The throttle position sensor signal voltage is
displayed.
THRTL SEN 2 [V]×
Throttle position sensor 2 signal is
converted by ECM internally. Thus, it
differs from ECM terminal voltage sig-
nal.
FUEL T/TEMP SE
[°C] or [°F]×

The fuel temperature (determined by the sig-
nal voltage of the fuel tank temperature sen-
sor) is displayed.
INT/A TEMP SE
[°C] or [°F]××

The intake air temperature (determined by the
signal voltage of the intake air temperature
sensor) is indicated.
EVAP SYS PRES
[V]×

The signal voltage of EVAP control system
pressure sensor is displayed.
FUEL LEVEL SE
[V]×

The signal voltage of the fuel level sensor is
displayed.
START SIGNAL
[ON/OFF]××

Indicates start signal status [ON/OFF] com-
puted by the ECM according to the signals of
engine speed and battery voltage.
After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS
[ON/OFF]××

Indicates idle position [ON/OFF] computed by
ECM according to the accelerator pedal posi-
tion sensor signal.
AIR COND SIG
[ON/OFF]××

Indicates [ON/OFF] condition of the air condi-
tioner switch as determined by the air condi-
tioner signal. Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSDescription Remarks

EC-228Revision: August 2007
DTC P0181 FTT SENSOR
2004 QX56
Diagnostic ProcedureUBS00H38
1. CHECK DTC WITH COMBINATION METER
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.
2. Turn ignition switch ON.
3. Check voltage between “fuel level sensor unit and fuel pump”
terminal 4 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
BBIA0354E
BBIA0583E
Voltage: Approximately 5V
PBIB0932E

DTC P0181 FTT SENSOR
EC-229
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EC
Revision: August 20072004 QX56
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors C1, E41

Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
>> Repair harness or connector.
5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination meter harness connector.
3. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 5 and combination
meter terminal 16. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors C1, E41

Harness connectors E152, M31

Harness for open or short between “fuel level sensor unit and fuel pump” and combination meter
>> Repair open circuit or short to ground or short to power in harness or connector.
7. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-229, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace fuel level sensor unit.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00H39
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.Continuity should exist.

DTC P0182, P0183 FTT SENSOR
EC-233
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00H3F
1. CHECK DTC WITH COMBINATION METER
Refer to DI-5, "
COMBINATION METERS" .
OK or NG
OK >> GO TO 2.
NG >> Go to DI-22, "
Fuel Level Sensor Unit Inspection" .
2. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-133, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3. CHECK FUEL TANK TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect “fuel level sensor unit and fuel pump” harness con-
nector.
2. Turn ignition switch ON.
3. Check voltage between “fuel level sensor unit and fuel pump”
terminal 4 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
BBIA0354E
BBIA0583E
Voltage: Approximately 5V
PBIB0932E

EC-234Revision: August 2007
DTC P0182, P0183 FTT SENSOR
2004 QX56
4. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors C1, E41

Harness for open or short between ECM and “fuel level sensor unit and fuel pump”
>> Repair harness or connector.
5. CHECK FUEL TANK TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination meter harness connector.
3. Check harness continuity between “fuel level sensor unit and fuel pump” terminal 5 and combination
meter terminal 16. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors C1, E41

Harness connectors E152, M31

Harness for open or short between “fuel level sensor unit and fuel pump” and combination meter
>> Repair open circuit or short to ground or short to power in harness or connector.
7. CHECK FUEL TANK TEMPERATURE SENSOR
Refer to EC-234, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace fuel level sensor unit.
8. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00H3G
FUEL TANK TEMPERATURE SENSOR
1. Remove fuel level sensor unit.Continuity should exist.