Page 1785 of 3371
EC-594Revision: August 2007
IGNITION SIGNAL
2004 QX56
3. Check resistance between condenser terminals 1 and 2.
Removal and InstallationUBS00HD4
IGNITION COIL WITH POWER TRANSISTOR
Refer to EM-26, "IGNITION COIL" .
Resistance Above 1 MΩ at 25°C (77°F)
PBIB0794E
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INJECTOR CIRCUIT
EC-595
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Revision: August 20072004 QX56
INJECTOR CIRCUITPFP:16600
Component DescriptionUBS00HD5
The fuel injector is a small, precise solenoid valve. When the ECM
supplies a ground to the injector circuit, the coil in the injector is
energized. The energized coil pulls the needle valve back and allows
fuel to flow through the injector into the intake manifold. The amount
of fuel injected depends upon the injection pulse duration. Pulse
duration is the length of time the injector remains open. The ECM
controls the injection pulse duration based on engine fuel needs.
CONSULT-II Reference Value in Data Monitor ModeUBS00HD6
Specification data are reference values.
SEF 3 75 Z
MONITOR ITEM CONDITION SPECIFICATION
B/FUEL SCHDL
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
No loadIdle 3.0 - 4.2 msec
2,000 rpm 3.0 - 4.2 msec
INJ PULSE-B1
INJ PULSE-B2
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
No loadIdle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
Page 1787 of 3371
EC-596Revision: August 2007
INJECTOR CIRCUIT
2004 QX56
Wiring DiagramUBS00HD7
BBWA11 90 E
Page 1788 of 3371

INJECTOR CIRCUIT
EC-597
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Revision: August 20072004 QX56
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 ProcedureUBS00HD8
1. INSPECTION START
Turn ignition switch to START.
Is any cylinder ignited?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
21
22
23
40
41
42
44
63O/L
BR
GR/W
Y/G
P
L
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GInjector No. 5
Injector No. 3
Injector No. 1
Injector No. 6
Injector No. 4
Injector No. 2
Injector No. 7
Injector No. 8[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm at idle.BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
Warm-up condition
Engine speed is 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
PBIB0042E
PBIB0043E
Page 1789 of 3371
EC-598Revision: August 2007
INJECTOR CIRCUIT
2004 QX56
2. CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine.
2. Perform “POWER BALANCE” in “ACTIVE TEST” mode with
CONSULT-II.
3. Make sure that each circuit produces a momentary engine
speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
Clicking noise should be heard.
OK or NG
OK >>INSPECTION END
NG >> GO TO 3.
PBIB0133E
PBIB1986E
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INJECTOR CIRCUIT
EC-599
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Revision: August 20072004 QX56
3. CHECK INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between injector terminal 1 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E2, F32
IPDM E/R connector E119
15A fuse
Harness for open or short between injector and fuse
>> Repair harness or connectors.
5. CHECK INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between injector terminal 2 and ECM terminals 21, 22, 23, 40, 41, 42, 44, 63.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.
Page 1791 of 3371
EC-600Revision: August 2007
INJECTOR CIRCUIT
2004 QX56
6. CHECK INJECTOR
Refer to EC-600, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace injector.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00HD9
INJECTOR
1. Disconnect injector harness connector.
2. Check resistance between terminals as shown in the figure.
Removal and InstallationUBS00HDA
INJECTOR
Refer to EM-29, "FUEL INJECTOR AND FUEL TUBE" . Resistance: 11.1 - 14.5Ω [at 10 - 60°C (50 - 140°F)]
PBIB1727E
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FUEL PUMP CIRCUIT
EC-601
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Revision: August 20072004 QX56
FUEL PUMP CIRCUITPFP:17042
DescriptionUBS00HDB
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the furl tank.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDC
Specification data are reference values.
Sensor Input signal to ECM ECM Function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and crankingOperates.
When engine is stoppedStops in 1.5 seconds.
Except as shown aboveSto ps.
BBIA0402E
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLY
For 1 second after turning ignition switch ON
Engine running or crankingON
Except above conditions OFF