ignition INFINITI QX56 2004 Factory Service Manual

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DRIVER INFORMATION SYSTEM
K ELECTRICAL
CONTENTS
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Revision: August 20072004 QX56 PRECAUTION ............................................................ 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Wiring Diagrams and Trouble Diagnosis .................. 3
PREPARATION ........................................................... 4
Commercial Service Tool ......................................... 4
COMBINATION METERS ........................................... 5
System Description .................................................. 5
UNIFIED METER CONTROL UNIT ...................... 5
POWER SUPPLY AND GROUND CIRCUIT ........ 6
WATER TEMPERATURE GAUGE ........................ 6
ENGINE OIL PRESSURE GAUGE ....................... 6
A/T OIL TEMPERATURE GAUGE ........................ 6
VOLTAGE GAUGE ................................................ 6
TACHOMETER ..................................................... 6
FUEL GAUGE ....................................................... 6
SPEEDOMETER ................................................... 6
CAN COMMUNICATION SYSTEM DESCRIP-
TION ...................................................................... 6
Component Parts and Harness Connector Location ..... 7
Combination Meter ................................................... 8
CHECK .................................................................. 8
Circuit Diagram ........................................................ 9
Wiring Diagram — METER — ................................ 10
Terminals and Reference Value for Combination
Meter ...................................................................... 12
Meter/Gauge Operation and Odo/Trip Meter ......... 13
SELF-DIAGNOSIS FUNCTION .......................... 13
HOW TO INITIATE COMBINATION METER
SELF- DIAGNOSIS MODE ................................. 13
COMBINATION METER SELF-DIAGNOSIS
MODE FUNCTIONS ........................................... 13
How to Proceed With Trouble Diagnosis ................ 17
Diagnosis Flow ....................................................... 17
Power Supply and Ground Circuit Inspection ........ 18
Symptom Chart ...................................................... 19
Vehicle Speed Signal Inspection ............................ 19
Engine Oil Pressure Signal Inspection ................... 19
Water Temperature Signal Inspection .................... 21Engine Speed Signal Inspection ............................. 21
Fuel Level Sensor Unit Inspection .......................... 22
FUEL LEVEL SENSOR UNIT ............................. 22
LOW-FUEL WARNING LAMP ............................. 22
Fuel Gauge Fluctuates, Indicates Wrong Value, or
Varies ...................................................................... 24
Fuel Gauge Does Not Move to Full-position ........... 24
Electrical Components Inspection .......................... 25
FUEL LEVEL SENSOR UNIT CHECK ................ 25
Removal and Installation of Combination Meter ..... 25
COMPASS AND THERMOMETER ........................... 26
System Description ................................................. 26
OUTSIDE TEMPERATURE DISPLAY ................. 26
DIRECTION DISPLAY ......................................... 26
Wiring Diagram — COMPAS — ............................. 27
Trouble Diagnoses ................................................. 28
PRELIMINARY CHECK FOR THERMOMETER ... 28
INSPECTION/COMPASS AND THERMOME-
TER ..................................................................... 28
Calibration Procedure for Compass ....................... 29
CORRECTION FUNCTIONS OF COMPASS ...... 29
INITIAL CORRECTION PROCEDURE FOR
COMPASS ........................................................... 30
WARNING LAMPS .................................................... 31
Schematic ............................................................... 31
Wiring Diagram — WARN — .................................. 32
Oil Pressure Warning Lamp Stays Off (Ignition
Switch ON) ............................................................. 38
Oil Pressure Warning Lamp Does Not Turn Off (Oil
Pressure Is Normal) ................................................ 40
A/T INDICATOR ........................................................ 41
Wiring Diagram — AT/IND — ................................. 41
A/T Indicator Does Not Illuminate ........................... 42
WARNING CHIME ..................................................... 43
Component Parts and Harness Connector Location ... 43
System Description ................................................. 44
FUNCTION .......................................................... 44
IGNITION KEY WARNING CHIME ..................... 44
LIGHT WARNING CHIME ................................... 44
SEAT BELT WARNING CHIME ........................... 44

COMBINATION METERS
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Revision: August 20072004 QX56
COMBINATION METERSPFP:24814
System DescriptionEKS007DL
UNIFIED METER CONTROL UNIT

Speedometer, odometer, tachometer, fuel gauge, oil pressure gauge, voltage meter, A/T temperature
gauge, and water temperature gauge are controlled by the unified meter control unit, which is built into the
combination meter.

Warning indicators are controlled by signals drawn from the CAN communication system, BCM (body con-
trol module), and components connected directly to the combination meter.

Digital meter is adopted for odometer/trip meters*, as well as the A/T position indicator display.
*The record of the odometer is kept even if the battery cable is disconnected.

Odometer/trip meters and A/T indicator segments can be checked in diagnosis mode.

Meters/gauges can be checked in diagnosis mode.
Illumination control
The unified meter control unit outputs the speedometer, odometer/trip meters, tachometer, oil pressure gauge,
voltage meter, A/T indicator, A/T temperature gauge, fuel and temperature gauge lighting when the ignition
switch is turned on. When the lighting switch is turned on, the illumination control switch can be used to adjust
the brightness of the combination meter illumination and the odometer/trip meters and meter illumination.
When the ignition switch is turned from the OFF to the ON position, the combination meter dial lighting will
remain off for 0.7 seconds. For additional combination meter illumination control information, refer to LT-152,
"System Description" .

DI-6
COMBINATION METERS
Revision: August 20072004 QX56
POWER SUPPLY AND GROUND CIRCUIT
Power is supplied at all times

through 10A fuse [No.19, located in the fuse block (J/B)]

to combination meter terminal 8.
With the ignition switch in the ON or START position, power is supplied

through 10A fuse [No.14, located in the fuse block (J/B)]

to combination meter terminal 24.
With the ignition switch in the ACC or ON position, power is supplied

through 10A fuse [No.4, located in the fuse block (J/B)]

to combination meter terminal 1.
Ground is supplied

to combination meter terminal 17

through body grounds M57, M61 and M79.
WATER TEMPERATURE GAUGE
The water temperature gauge indicates the engine coolant temperature.
ECM provides an engine coolant temperature signal to combination meter via CAN communication lines.
ENGINE OIL PRESSURE GAUGE
The engine oil pressure gauge indicates the engine oil pressure.
The engine oil pressure gauge is regulated by the unified meter control unit and input from the oil pressure
sensor.
A/T OIL TEMPERATURE GAUGE
The A/T oil temperature gauge indicates the A/T fluid temperature.
TCM (transmission control module) provides an A/T fluid temperature signal to combination meter via CAN
communication lines.
V O LTA G E G A U G E
The voltage gauge indicates the battery/charging system voltage.
The voltage gauge is regulated by the unified meter control unit.
TACHOMETER
The tachometer indicates engine speed in revolutions per minute (rpm).
ECM provides an engine speed signal to combination meter via CAN communication lines.
FUEL GAUGE
The fuel gauge indicates the approximate fuel level in the fuel tank.
The fuel gauge is regulated by the unified meter control unit and a variable resistor signal supplied

to combination meter terminal 15.

through fuel level sensor unit and fuel pump terminal 2

through fuel level sensor unit and fuel pump terminal 5

from combination meter terminal 16
SPEEDOMETER
ABS actuator and electric unit (control unit) provides a vehicle speed signal to the combination meter via CAN
communication lines.
CAN COMMUNICATION SYSTEM DESCRIPTION
Refer to LAN-5, "CAN COMMUNICATION" .

DI-12
COMBINATION METERS
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Terminals and Reference Value for Combination MeterEKS007DQ
Te r m i n a l
No.Wire
colorItemCondition
Reference value (V)
(Approx.) Ignition
switchOperation or condition
1OIgnition switch ACC or
ONACC — Battery voltage
8 Y/R Battery power supply OFF — Battery voltage
11 W C A N - H — — —
12 R CAN-L — — —
15 Y/L Fuel level sensor signal — —Refer to DI-22, "
Fuel Level Sensor
Unit Inspection" .
16 B/PFuel level sensor and oil
pressure sensor groundON — 0V
17 B Ground OFF — 0V
18 BR Illumination control switch — Lighting switch ONRefer to LT-153, "
ILLUMINATION
OPERATION BY LIGHTING
SWITCH" .
20 YOil pressure sensor sig-
nalON — 0 - 5V
22 GR/LOil pressure sensor refer-
ence voltageON — 5V
24 O/LIgnition switch ON or
STARTON — Battery voltage

COMBINATION METERS
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Meter/Gauge Operation and Odo/Trip MeterEKS007DR
SELF-DIAGNOSIS FUNCTION
The following items can be checked during Combination Meter Self-Diagnosis Mode.

Gauge sweep and present gauge values.

Illuminates all odometer, fuel, and engine temperature segments.

Illuminates all micro controlled lamps/LED's regardless of switch configuration.

Displays estimated present battery voltage.

Displays seat belt buckle switch LH status.
HOW TO INITIATE COMBINATION METER SELF- DIAGNOSIS MODE
NOTE:
Once entered, Combination Meter Self-Diagnosis Mode will function with the ignition switch in ON or START.
Combination Meter Self-Diagnosis Mode will exit upon turning the ignition switch to OFF or ACC.
To initiate Combination Meter Self-Diagnosis Mode, refer to the following procedure.
1. Turn the ignition switch ON, while holding the odometer/trip meter switch for 5 - 8 seconds.
NOTE:
If the diagnosis function is activated the odometer/trip meter will display tESt.
COMBINATION METER SELF-DIAGNOSIS MODE FUNCTIONS
To interpret Combination Meter Self-Diagnosis Mode functions, refer to the following table.
Event Odometer Display Description of Test/Data Notes:
Odometer/trip meter A/B
switch held from 5 to 8
seconds (or until
released)tESt Initiating self-diagnosis mode
Odometer/trip meter A/B
switch engaged and
released = next test
requestedrXXXX, FAILReturn to normal opera-
tion of all lamps/LEDs and
displays hex ROM rev. If
a ROM checksum fault
exists, display alternates
between "r XXXX" and
"FAIL".
Next test requested nrXXXXDisplays hex ROM rev as
stored in NVM.
Next test requested GAGEPerforms sweep of all
gauges, then displays
present gauge values.
Performs checksum tests
on ROM and EE.Gauges sweep within 10 sec-
onds
Next test requested (All segments illuminated)Lights all odometer/trip
meter, fuel, and engine
temperature display seg-
ments.Initiating self-diagnosis mode
complete
Next test requested bulbIlluminates all micro-con-
trolled lamps/LEDs
regardless of SW configu-
ration.
Next test requested EE XX, FAILHex EE level. If EE
checksum fault exists,
display alternates
between "EE XX" and
"FAIL".
Next test requested dtXXXXHex coding of final manu-
facturing test date.

COMBINATION METERS
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How to Proceed With Trouble DiagnosisEKS007DS
1. Confirm the symptom or customer complaint.
2. Perform diagnosis according to diagnosis flow. Refer to DI-17, "
Diagnosis Flow" .
3. According to the symptom chart, repair or replace the cause of the symptom.
4. Does the meter operate normally? If so, go to 5. If not, go to 2.
5. Inspection End.
Diagnosis FlowEKS007DT
1. CHECK WARNING INDICATOR ILLUMINATION
1. Turn ignition switch ON.
2. Make sure warning indicators (such as malfunction indicator lamp and oil pressure low/coolant tempera-
ture high warning indicator) illuminate.
Do warning indicators illuminate?
YES >> GO TO 2.
NO >> Check ignition power supply system of combination meter. Refer to DI-18, "
Power Supply and
Ground Circuit Inspection" .
2. CHECK SELF-DIAGNOSIS OPERATION OF COMBINATION METER
Perform combination meter self-diagnosis. Refer to DI-13, "
SELF-DIAGNOSIS FUNCTION" .
Does self-diagnosis function operate?
YES >> GO TO 3.
NO >> Check the following.

Combination meter power supply and ground circuit. Refer to DI-18, "Power Supply and
Ground Circuit Inspection" .
3. CHECK ODOMETER OPERATION
Check segment display status of odometer.
Is the display normal?
YES >> GO TO 4.
NO >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
4. CHECK COMBINATION METER CIRCUIT
Check indication of each meter/gauge in self-diagnosis mode.
OK or NG
OK >> Go to DI-19, "Symptom Chart" .
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
WKIA1531E
WKIA1814E

DI-18
COMBINATION METERS
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Power Supply and Ground Circuit InspectionEKS007DU
1. CHECK FUSES
Check for blown combination meter fuses.
Refer to DI-10, "Wiring Diagram — METER —" .
OK or NG
OK >> GO TO 2.
NG >> If fuse is blown, be sure to eliminate cause of malfunction before installing new fuse. Refer to PG-
4, "POWER SUPPLY ROUTING CIRCUIT" .
2. CHECK POWER SUPPLY CIRCUIT
1. Disconnect combination meter connector.
2. Check voltage between combination meter harness connector
terminals and ground.
OK or NG
OK >> GO TO 3.
NG >> Check the harness for open between combination meter and fuse.
3. CHECK GROUND CIRCUIT
Check continuity between combination meter harness connector ter-
minals and ground.
OK or NG
OK >> Inspection End.
NG >> Repair harness or connector.
Unit Power source Fuse No.
Combination meter Battery 19
Ignition switch ON or START 14
Ignition switch ACC or ON 4
Terminals Ignition switch position
(+)
(–) OFF ACC ON
ConnectorTe r m i n a l
(Wire color)
M241 (O)
Ground0VBattery
voltageBattery
voltage
8 (Y/R)Battery
voltageBattery
voltageBattery
voltage
24 (O/L) 0V 0VBattery
voltage
WKIA1815E
Te r m i n a l s
Continuity (+)
(–)
ConnectorTe r m i n a l
(Wire color)
M24 17 (B) Ground Yes
WKIA1526E

COMBINATION METERS
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Symptom ChartEKS007DV
Vehicle Speed Signal InspectionEKS007DW
1. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS
Refer to BRC-29, "
SELF-DIAGNOSIS" .
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combination Meter" .
NG >> Perform the "Diagnostic Procedure" for displayed DTC. Refer to BRC-11, "
TROUBLE DIAGNO-
SIS" .
Engine Oil Pressure Signal Inspection EKS0086D
1. CHECK OIL PRESSURE SENSOR SIGNAL
1. Turn ignition switch ON.
2. Check voltage between combination meter harness connector
M24 terminal 20 (Y) and ground.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
Trouble phenomenon Possible cause
Improper tachometer indication. Refer to DI-21, "
Engine Speed Signal Inspection" .
Improper water temperature gauge indication. Refer to DI-21, "
Water Temperature Signal Inspection" .
Improper speedometer or odometer. Refer to DI-19, "
Vehicle Speed Signal Inspection" .
Improper fuel gauge indication.
Refer to DI-22, "
Fuel Level Sensor Unit Inspection" .
Fuel warning lamp indication is irregular.
Improper A/T oil temperature gauge indicationRefer to AT-131, "
DTC P1710 A/T FLUID TEMPERATURE SEN-
SOR CIRCUIT" .
Improper voltage gauge indication
Replace combination meter. Refer to IP-13, "
Combination Meter"
.
More than one gauge does not give proper indication.
Improper A/T position indication. Refer to DI-41, "
A/T INDICATOR" .
Illumination control does not operate properly. Refer to LT-152, "
ILLUMINATION" .
Te r m i n a l s
Condition Voltage (V) (+)
(–)
ConnectorTe r m i n a l
(Wire color)
M24 20 (Y) GroundWhen ignition switch is in ON
position. (Engine stopped)Ye s
Engine running. (Idle speed) Yes
WKIA1833E

DI-20
COMBINATION METERS
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2. CHECK OIL PRESSURE SENSOR GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect combination meter connector M24 and oil pressure
sensor connector F4.
3. Check continuity between combination meter harness connector
M24 terminal 16 (B/P) and oil pressure sensor harness connec-
tor F4 terminal 3 (B/P).
OK or NG
OK >> Replace the combination meter. Refer to IP-13, "Combi-
nation Meter" .
NG >> Repair harness or connector.
3. CHECK OIL PRESSURE SENSOR REFERENCE VOLTAGE
1. Turn ignition switch OFF.
2. Disconnect oil pressure sensor connector F4.
3. Turn ignition switch ON.
4. Check voltage between combination meter harness connector
M24 terminal 22 (GR/L) and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" .
4. CHECK OIL PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect combination meter connector M24.
3. Check continuity between combination meter harness connector M24 terminal 22 (GR/L) and oil pressure
sensor harness connector F4 terminal 1 (GR/L).
4. Check continuity between combination meter harness connector
M24 terminal 22 (GR/L) and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair harness or connector.Continuity should exist.
WKIA1837E
Voltage : Approx. 5V
WKIA1834E
Continuity should exist.
Continuity should not exist.
WKIA1835E

DI-22
COMBINATION METERS
Revision: August 20072004 QX56
Fuel Level Sensor Unit InspectionEKS007DZ
FUEL LEVEL SENSOR UNIT
The following symptoms do not indicate a malfunction.

Depending on vehicle position or driving circumstance, the fuel in the tank shifts and the indication may
fluctuate.

If the vehicle is fueled with the ignition switch ON, the indication will update slowly.

If the vehicle is tilted when the ignition switch is turned ON, fuel in the tank may flow to one direction
resulting in a change of reading.
LOW-FUEL WARNING LAMP
Depending on vehicle posture or driving circumstances, the fuel level in the tank varies, and the warning lamp
ON timing may be changed.
1. CHECK SELF-DIAGNOSIS
Perform the combination meter self-diagnosis. Refer to DI-13, "
SELF-DIAGNOSIS FUNCTION" .
OK or NG
OK >> GO TO 2.
NG >> Replace the combination meter. Refer to IP-13, "
Combination Meter" .
2. CHECK HARNESS CONNECTOR
1. Turn the ignition switch OFF.
2. Check combination meter and fuel level sensor unit and fuel pump terminals (meter-side, and harness-
side) for poor connection.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace terminals or connectors.
3. CHECK HARNESS CONNECTOR OUTPUT SIGNAL
1. Disconnect fuel level sensor unit and fuel pump connector.
2. Turn ignition switch ON.
3. Check voltage between combination meter harness connector
M24 terminal 15 (Y/L) and ground.
OK or NG
OK >> GO TO 4.
NG >> Replace the combination meter. Refer to IP-13, "
Combi-
nation Meter" . Battery voltageWKIA1816E