battery voltage INFINITI QX56 2008 Factory Service Manual

EC-396
< COMPONENT DIAGNOSIS >[VK56DE]
COOLING FAN
2. Supply cooling fan motor terminals with battery voltage and
check operation.
Cooling fan motor should operate.
If NG, replace cooling fan motor.
AWBIA0529ZZ
Revision: March 2010 2008 QX56

EC-400
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL INJECTOR
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with
CONSULT-IIl 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 fuel injector and fuse
>> Repair harness or connectors.
5.CHECK FUEL INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between fuel 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.
6.CHECK FUEL INJECTOR
Refer to EC-401, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning fuel injector.
7.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.
Revision: March 2010
2008 QX56

EC-402
< COMPONENT DIAGNOSIS >[VK56DE]
FUEL PUMP
FUEL PUMP
DescriptionINFOID:0000000001365881
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 EC M 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 fuel tank.
Diagnosis ProcedureINFOID:0000000001365884
1.CHECK OVERALL FUNCTION
1. Turn ignition switch ON.
2. Pinch fuel feed hose with two fingers.
OK or NG
OK >> INSPECTION END
NG >> GO TO 2.
2.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Turn ignition switch ON.
Sensor Input signal to ECMECM FunctionActuator
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 cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Stops.
BBIA0402E
Fuel pressure pulsation should be felt on the fuel feed
hose for 1 second after igniti on switch is turned ON.
BBIA0357E
Revision: March 2010 2008 QX56

FUEL PUMPEC-403
< COMPONENT DIAGNOSIS > [VK56DE]
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4. Check voltage between ECM terminal 113 and ground with
CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 3.
3.CHECK FUEL PUMP POWER SUPPLY CIRCUIT-II
Check voltage between IPDM E/R terminal 46 and ground with
CONSULT-IIl or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 13.
4.DETECT MALFUNCTIONING PART
Check harness for open or short between IPDM E/R and ECM.
>> Repair harness or connectors.
5.CHECK CONDENSER-2 POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Disconnect condenser-2 harness connector.
4. Turn ignition switch ON.
5. Check voltage between condenser-2 terminal 1 and ground with CONSULT-IIl or tester.
6. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6.CHECK 15A FUSE
1. Turn ignition switch OFF. Voltage: Battery voltage
PBIB1187E
Voltage: Battery voltage
PBIB2656E
BBIA0388E
Voltage: Battery voltage should exist for 1 sec-
ond after ignition switch is turned ON.
PBIB0624E
Revision: March 2010 2008 QX56

EC-406
< COMPONENT DIAGNOSIS >[VK56DE]
ICC BRAKE SWITCH
ICC BRAKE SWITCH
Component DescriptionINFOID:0000000001365887
When depress on the brake pedal, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal)
Refer to
CCS-13
for the ICC function.
Diagnosis ProcedureINFOID:0000000001365890
1.CHECK OVERALL FUNCTION-I
With CONSULT-IIl
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-IIl.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-IIl
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK OVERALL FUNCTION-II
With CONSULT-IIl
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-IIl
BBIA0470E
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITIONVOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
CONDITIONINDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
Revision: March 2010 2008 QX56

ICC BRAKE SWITCHEC-407
< COMPONENT DIAGNOSIS > [VK56DE]
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Check voltage between ECM terminal 101 and ground under the fol-
lowing conditions.
OK or NG
OK >>
INSPECTION END
NG >> GO TO 10.
3.CHECK DTC WITH ICC UNIT
Refer to CCS-18
.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK ICC BRAKE HOLD RELAY POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ICC brake hold relay.
3. Turn ignition switch ON.
4. Check voltage between ICC brake hold relay terminal 4 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Fuse block (J/B) connector M4
• 10A fuse
• Harness for open or short between ICC brake hold relay and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK ICC BRAKE SWITCH POWER SUPPLY CIRCUIT
CONDITION VOLTAGE
Brake pedal: Fully released Approximately 0V
Brake pedal: Slightly depressed Battery voltage
PBIB1537E
BBIA0471E
Voltage: Battery voltage
MBIB0059E
Revision: March 2010 2008 QX56

ICC BRAKE SWITCHEC-409
< COMPONENT DIAGNOSIS > [VK56DE]
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3. Check voltage between stop lamp switch terminal 3 and ground
with CONSULT -IIl or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Fuse block (J/B) No. 1 connector M60
• 10A fuse
• Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
12.CHECK STOP LAMP SWITCH INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4. Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
13.CHECK STOP LAMP SWITCH
Refer to EC-409, "
Component Inspection".
OK or NG
OK >> GO TO 14.
NG >> Replace stop lamp switch.
14.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001365891
ICC BRAKE SWITCH
1. Turn ignition switch OFF.
2. Disconnect ICC brake switch harness connector. Voltage: Battery voltage
PBIB2102E
Continuity should exist.
Revision: March 2010
2008 QX56

EC-412
< COMPONENT DIAGNOSIS >[VK56DE]
IGNITION SIGNAL
OK >>
INSPECTION END
NG >> GO TO 10.
4.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
2. Check voltage between ECM terminals 119, 120 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 5.
NG >> Go to EC-83
.
5.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect condenser-1 harness connector.
3. Turn ignition switch ON.
4. Check voltage between condenser-1 terminal 1 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 6.
6.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector E119.
3. Check harness continuity between IPDM E/R terminal 4 and condenser-1 terminal 1. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> Go to EC-83.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32 Voltage: Battery voltage
MBIB0034E
BBIA0358E
Voltage: Battery voltage
PBIB0624E
Continuity should exist.
Revision: March 2010
2008 QX56

IGNITION SIGNALEC-413
< COMPONENT DIAGNOSIS > [VK56DE]
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• Harness for open or short between condenser-1 and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK CONDENSER-1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between condenser-1 terminal 2 and ground. Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to power in harness or connectors.
9.CHECK CONDENSER-1
Refer to EC-414, "
Component Inspection".
OK or NG
OK >> GO TO 10.
NG >> Replace condenser-1.
10.CHECK IGNITION COIL POWER SUPPLY CIRCUIT-IV
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Disconnect ignition coil harness connector.
4. Turn ignition switch ON.
5. Check voltage between ignition coil terminal 3 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• Harness for open or short between ignition coil and harness connector F32 Continuity should exist.
1. Ignition coils (with power transistor)
(bank 2) 2. Ignition coils (with power transistor)
(bank 1)
Voltage: Battery voltage
BBIA0777E
PBIB0138E
Revision: March 2010 2008 QX56

EC-428
< ECU DIAGNOSIS >[VK56DE]
ECM
*1: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, the
y differ
from ECM terminals voltage signal.
*2: Before measuring the terminal voltage, confirm the battery is fully charged. Refer to PG-73
.
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-IIl value with the speedometer
indication. Almost the same speed as the
speedometer indication
TRVL AFTER MIL • Ignition switch: ON Vehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,723 mile)
A/F S1 HTR (B1)
A/F S1 HTR (B2) • Engine: After warming up, idle the engine
4 - 100%
AC PRESS SEN • Engine: Idle
• Both A/C switch and blower fan switch: ON (Compressor operates.)
1.0 - 4.0V
VHCL SPEED SE • Turn drive wheels and compare CONSULT-IIl value with the speedometer
indication. Almost the same speed as the
speedometer indication
SET VHCL SPD • Engine: Running ASCD: Operating.The preset vehicle speed is dis-
played.
MAIN SW • Ignition switch: ON MAIN switch: Pressed
ON
MAIN switch: Released OFF
CANCEL SW • Ignition switch: ON CANCEL switch: Pressed
ON
CANCEL switch: Released OFF
RESUME/ACC SW • Ignition switch: ON RESUME/ACCELERATE switch:
Pressed
ON
RESUME/ACCELERATE switch: Re-
leased OFF
SET SW • Ignition switch: ON SET/COAST switch: Pressed
ON
SET/COAST switch: Released OFF
DIST SW • Ignition switch: ON DISTANCE switch: Pressed
ON
DISTANCE switch: Released OFF
BRAKE SW1 • Ignition switch: ON Brake pedal: Fully released
ON
Brake pedal: Slightly depressed OFF
BRAKE SW2 • Ignition switch: ON Brake pedal: Fully released
OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP • Ignition switch: ON MAIN switch: Pressed at the 1st time
→ at the 2nd timeON
→ OFF
SET LAMP • MAIN switch: ON
• Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH) ASCD: Operating
ON
ASCD: Not operating OFF
ALT DUTY • Engine: Idle 0 - 80%
BAT CUR SEN • Engine speed: Idle
• Battery: Fully charged*
2
• Selector lever: P or N
• Air conditioner switch: OFF
•No load Approx. 2,600 - 3,500mV
ALT DUTY SIG • Power generation voltage variable control: Operating
ON
• Power generation voltage variable control: Not operating OFF
MONITOR ITEM
CONDITION SPECIFICATION
Revision: March 2010 2008 QX56