2007 INFINITI QX56 service

IGNITION SIGNAL
EC-633
< SERVICE INFORMATION >
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2. Read the voltage signal between ECM terminals 46, 60, 61, 62,
65, 79, 80, 81 and ground with an oscilloscope.
3. Verify that the oscilloscope screen shows the signal wave as
shown below.
NOTE:
The pulse cycle changes depending on rpm at idle.
OK or NG
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-II or tester.
OK or NG
OK >> GO TO 5.
NG >> Go to EC-139
.
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-II 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.
PBIB2094E
PBIB0044E
Voltage: Battery voltage
MBIB0034E
BBIA0358E
Voltage: Battery voltage
PBIB0624E

EC-634
< SERVICE INFORMATION >
IGNITION SIGNAL
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-139.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• 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-635, "
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.Continuity should exist.
Continuity should exist.
1. Ignition coils (with power transistor)
(bank 2)2. Ignition coils (with power transistor)
(bank 1)
BBIA0777E

IGNITION SIGNAL
EC-635
< SERVICE INFORMATION >
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5. Check voltage between ignition coil terminal 3 and ground with
CONSULT-II 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
>> Repair or replace harness or connectors.
12.CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between ignition coil terminal 2 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 13.
NG >> Repair open circuit or short to power in harness or connectors.
13.CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 46, 60, 61, 62, 65, 79, 80, 81 and ignition coil terminal
1.
Refer to Wiring Diagram.
3. Also check harness for short to ground and 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 IGNITION COIL WITH POWER TRANSISTOR
Refer to EC-635, "
Component Inspection".
OK or NG
OK >> GO TO 15.
NG >> Replace ignition coil with power transistor.
15.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003532180
IGNITION COIL WITH POWER TRANSISTOR
CAUTION:Voltage: Battery voltage
PBIB0138E
Continuity should exist.
Continuity should exist.

EC-636
< SERVICE INFORMATION >
IGNITION SIGNAL
Do the following procedure in the place where ventilation is good without the combustible.
1. Turn ignition switch OFF.
2. Disconnect ignition coil harness connector.
3. Check resistance between ignition coil terminals as follows.
4. If NG, replace ignition coil with power transistor.
If OK, go to next step.
5. Turn ignition switch OFF.
6. Reconnect all harness connectors disconnected.
7. Remove fuel pump fuse in fuse block No. 1 to release fuel pres-
sure.
NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.
8. Start engine.
9. After engine stalls, crank it two or three times to release all fuel
pressure.
10. Turn ignition switch OFF.
11. Remove all ignition coil harness connectors to avoid the electri-
cal discharge from the ignition coils.
12. Remove ignition coil and spark plug of the cylinder to be
checked.
13. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
14. Connect spark plug and harness connector to ignition coil.
15. Fix ignition coil using a rope etc. with gap of 13 - 17 mm
between the edge of the spark plug and grounded metal portion
as shown in the figure.
16. Crank engine for about 3 seconds, and check whether spark is
generated between the spark plug and the grounded metal por-
tion.
CAUTION:
• Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.
• It might cause to damage the ignition coil if the gap of more than 17 mm is taken.
NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.
17. If NG, replace ignition coil with power transistor.
CONDENSER-1
1. Turn ignition switch OFF.
2. Disconnect condenser-1 harness connector.
Terminal No. (Polarity) Resistance Ω [at 25°C (77°F)]
1 and 2 Except 0 or ∞
1 and 3
Except 0
2 and 3
Spark should be generated.
PBIB0847E
BBIA0380E
PBIB2325E

IGNITION SIGNAL
EC-637
< SERVICE INFORMATION >
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3. Check resistance between condenser-1 terminals 1 and 2.
Removal and InstallationINFOID:0000000003532181
IGNITION COIL WITH POWER TRANSISTOR
Refer to EM-28.
Resistance Above 1 MΩ at 25°C (77°F)
PBIB0794E

EC-638
< SERVICE INFORMATION >
REFRIGERANT PRESSURE SENSOR
REFRIGERANT PRESSURE SENSOR
Component DescriptionINFOID:0000000003532182
The refrigerant pressure sensor is installed at the condenser of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan system.
BBIA0445E
PBIB2657E

REFRIGERANT PRESSURE SENSOR
EC-639
< SERVICE INFORMATION >
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Wiring DiagramINFOID:0000000003532183
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.
BBWA1715E

EC-640
< SERVICE INFORMATION >
REFRIGERANT PRESSURE SENSOR
Diagnosis Procedure
INFOID:0000000003532184
1.CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ON.
3. Check voltage between ECM terminal 70 and ground with CON-
SULT-II or tester.
OK or NG
OK >>INSPECTION END
NG >> GO TO 2.
2.CHECK GROUND CONNECTIONS
1. Turn A/C switch and blower switch OFF.
2. Turn ignition switch OFF.
3. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace ground connections.
3.CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
TER-
MI-
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NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 R/YSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
67 B Sensor ground[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
70 B/W Refrigerant pressure sensor[Engine is running]
•Warm-up condition
• Both A/C switch and blower switch: ON
(Compressor: Operates)1.0 - 4.0V
Voltage: 1.0 - 4.0V
PBIB1188E
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