2007 INFINITI QX56 service

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-137
< SERVICE INFORMATION >
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30.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “DATA MONITOR (SPEC)” mode, and then make sure that the indication is within
the SP value.
OK or NG
OK >>INSPECTION END
NG >> Detect malfunctioning part according to EC-90, "
Symptom Matrix Chart" .

EC-138
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT
DescriptionINFOID:0000000003531634
Intermittent incidents may occur. In many cases, the malfunction resolves itself (the part or circuit function
returns to normal without intervention). It is important to realize that the symptoms described in the customer's
complaint often do not recur on (1st trip) DTC visits. Realize also that the most frequent cause of intermittent
incidents occurrences is poor electrical connections. Because of this, the conditions under which the incident
occurred may not be clear. Therefore, circuit checks made as part of the standard diagnostic procedure may
not indicate the specific malfunctioning area.
Common Intermittent Incidents Report Situations
Diagnosis ProcedureINFOID:0000000003531635
1.INSPECTION START
Erase (1st trip) DTCs. Refer to EC-49, "
Emission-related Diagnostic Information" .
>> GO TO 2.
2.CHECK GROUND TERMINALS
Check ground terminals for corroding or loose connection.
Refer to EC-143, "
Ground Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3.SEARCH FOR ELECTRICAL INCIDENT
Perform GI-25, "
How to Perform Efficient Diagnosis for an Electrical Incident", “INCIDENT SIMULATION
TESTS”.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CHECK CONNECTOR TERMINALS
Refer to GI-22, "
How to Check Terminal", “HOW TO PROBE CONNECTORS”, “How to Check Enlarged Con-
tact Spring of Terminal”.
OK or NG
OK >>INSPECTION END
NG >> Repair or replace connector.
STEP in Work Flow Situation
2 The CONSULT-II is used. The SELF-DIAG RESULTS screen shows time data other than [0] or [1t].
3 or 4 The symptom described by the customer does not recur.
5 (1st trip) DTC does not appear during the DTC Confirmation Procedure.
10 The Diagnostic Procedure for PXXXX does not indicate the malfunctioning area.

POWER SUPPLY AND GROUND CIRCUIT
EC-139
< SERVICE INFORMATION >
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POWER SUPPLY AND GROUND CIRCUIT
Wiring DiagramINFOID:0000000003531636
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.
BBWA2088E

EC-140
< SERVICE INFORMATION >
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis Procedure
INFOID:0000000003531637
1.INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Ye s > > G O T O 8 .
No >> GO TO 2.
2.CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF and then ON.
2. Check voltage between ECM terminal 109 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• 10A fuse
• Harness for open or short between ECM and fuse
>> Repair harness or connectors.
4.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]
• Idle speedBody ground
109 L/W Ignition switch[Ignition switch: OFF]0V
[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 5
11 6B
B/WECM ground[Engine is running]
• Idle speedBody ground
11 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0015E

POWER SUPPLY AND GROUND CIRCUIT
EC-141
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Refer to EC-143, "Ground Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Repair or replace ground connections.
5.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F32, E2
• Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
7.CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> Go to EC-626 .
NG >> GO TO 8.
8.CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and then OFF.
BBIA0354E
Continuity should exist.
Voltage: Battery voltage
PBIB2063E

EC-142
< SERVICE INFORMATION >
POWER SUPPLY AND GROUND CIRCUIT
3. Check voltage between ECM terminals 119, 120 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 13.
NG (Battery voltage does not exist.)>>GO TO 9.
NG (Battery voltage exists for more than a few seconds.)>>GO TO
11 .
9.CHECK ECM POWER SUPPLY CIRCUIT-IV
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Check voltage between ECM terminal 111 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10.CHECK ECM POWER SUPPLY CIRCUIT-V
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminals 119, 120 and IPDM E/R terminal 3.
Refer to Wiring Diagram.
4. 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.
11 .CHECK ECM POWER SUPPLY CIRCUIT-VI
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminal 111 and IPDM E/R terminal 7.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 12.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
12.CHECK 20A FUSE
1. Disconnect 20A fuse from IPDM E/R.
2. Check 20A fuse.
OK or NG
OK >> GO TO 16.
NG >> Replace 20A fuse.Voltage: After turning ignition switch OFF, battery
voltage will exist for a few seconds, then drop
approximately 0V.
PBIB1630E
Voltage: Battery voltage
PBIB1191E
Continuity should exist.
Continuity should exist.

POWER SUPPLY AND GROUND CIRCUIT
EC-143
< SERVICE INFORMATION >
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13.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body.
Refer to EC-143, "
Ground Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Repair or replace ground connections.
14.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 1, 115, 116 and ground.
Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 16.
NG >> GO TO 15.
15.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors F32, E2
• Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
16.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair open circuit or short to power in harness or connectors.
Ground InspectionINFOID:0000000003531638
Ground connections are very important to the proper operation of electrical and electronic circuits. Ground
connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can
become an unwanted resistance. This unwanted resistance can change the way a circuit works.
Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can drasti-
cally affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit. Even
when the ground connection looks clean, there can be a thin film of rust on the surface.
When inspecting a ground connection follow these rules:
• Remove the ground bolt or screw.
• Inspect all mating surfaces for tarnish, dirt, rust, etc.
• Clean as required to assure good contact.
• Reinstall bolt or screw securely.
• Inspect for “add-on” accessories which may be interfering with the ground circuit.
BBIA0354E
Continuity should exist.

EC-144
< SERVICE INFORMATION >
POWER SUPPLY AND GROUND CIRCUIT
• If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the
wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one eye-
let make sure no ground wires have excess wire insulation.
For detailed ground distribution information, refer to PG-29, "
Ground Distribution".
PBIB1870E