2011 INFINITI QX56 ignition

EC-168
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
POWER SUPPLY AND GROUND CIRCUIT
POWER SUPPLY AND GROUND CIRCUIT
Diagnosis ProcedureINFOID:0000000006217763
1.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check the continuity between ECM harness connector and ground.
3. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Loose or poor connection for each connector and harness
 Harness for open or short between ECM and ground
>> Repair open circuit or short to power in harness or connectors.
3.CHECK ECM POWER SUPPLY CIRCUIT-I
1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check the voltage between ECM harness connector terminals.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 10 A fuse (No. 62)
 Loose or poor connection for each connector and harness
 Harness for open or short between ECM and fuse
>> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK ECM POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Check the voltage between ECM harness connector terminals as per the following.
ECM Ground Continuity
Connector Terminal
F 111 1 0 Ground Existed
E80 174
175
ECM
Vo l ta g e
Connector +–
Terminal Terminal
E80 141 175 Battery voltage
Revision: 2010 May2011 QX56

POWER SUPPLY AND GROUND CIRCUITEC-169
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 8.
6.CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch ON.
2. Check the voltage between IPDM E/R harness connector and ground.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace IPDM E/R. Refer to PCS-32, "
Removal and Installation".
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
8.CHECK ECM POWER SUPPLY CIRCUIT-IV
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Check the voltage between ECM harness connector terminals as per the following.
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 9.
9.CHECK ECM POWER SUPPLY CIRCUIT-V
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector.
3. Check the continuity between ECM harne ss connector and IPDM E/R harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 11.
NO >> GO TO 10.
10.DETECT MALFUNCTIONING PART
ECM Vo l ta g e
Connector +–
Terminal Terminal
E80 171
175After turning ignition switch OFF, battery
voltage will exist for a few seconds, then
drop to approximately 0 V.
172
IPDM E/R
Ground Voltage
Connector Terminal
E15 61 Ground Battery voltage
ECM Vol tag e
Connector +–
Terminal Terminal
E80 163 175 Battery voltage
ECM IPDM E/R Continuity
Connector Terminal Connector Terminal
E80 163 E14 41 Existed
Revision: 2010 May2011 QX56

U0101 CAN COMM CIRCUITEC-171
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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U0101 CAN COMM CIRCUIT
DTC LogicINFOID:0000000006217764
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check DTC.
Is DTC detected?
YES >> EC-171, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217765
Perform the trouble diagnosis for CAN communication system. Refer to LAN-18, "Trouble Diagnosis Flow
Chart".
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
U0101 LOST COMM (TCM)
(Lost communication with TCM) When ECM is not transmitting or receiving
CAN communication signal of OBD (emis-
sion related diagnosis) with TCM for 2 sec-
onds or more.  CAN communication line betrween
TCM and ECM
(CAN communication line is open or
shorted)
Revision: 2010 May2011 QX56

EC-172
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
U1001 CAN COMM CIRCUIT
U1001 CAN COMM CIRCUIT
DTC LogicINFOID:0000000006217768
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> EC-172, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217769
Perform the trouble diagnosis for CA N communication system. Refer to LAN-18, "Trouble Diagnosis Flow
Chart".
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
U1001 CAN COMM CIRCUIT
(CAN communication line) When ECM is not transmitting or receiving
CAN communication signal other than OBD
(emission related diagnosis) for 2 seconds
or more.  Harness or connectors
(CAN communication line is open or
shorted)
Revision: 2010 May2011 QX56

U0113, U1003 CAN COMM CIRCUITEC-173
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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U0113, U1003 CAN COMM CIRCUIT
DTC LogicINFOID:0000000006412037
DTC DETECTION LOGIC
NOTE:
If DTC U0113 or U1003 is displayed with DTC P
0607, first perform the trouble diagnosis for DTC P0607.
Refer to EC-378, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is 10 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check DTC.
Is DTC detected?
YES >> Proceed to EC-173, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006412038
1.CHECK VVEL CAN COMMUNICATION CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect VVEL control module harness connector.
4. Check the continuity between ECM harness c onnector and VVEL control module harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and VVEL control module
 Loose or poor connection for each connector and harness
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
U0113 CAN COMM CIRCUIT
(Lost communicat ion with VVEL
control module) When ECM is not transmitting or receiving
CAN communication signal of OBD (emis-
sion related diagnosi
s) with VVEL control
module for 2 seconds or more.  Harness or connectors
(VVEL CAN communication line is
open or shorted)
ECM
 VVEL control module
U1003 When ECM is not transmitting or receiving
CAN communication signal other than OBD
(emission related di
agnosis) with VVEL
control module for 2 seconds or more.
ECM VVEL control module Continuity
Connector Terminal Connector Terminal
E80 161
F56 24
Existed
166 11
Revision: 2010 May2011 QX56

EC-174
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
U0113, U1003 CAN COMM CIRCUIT
>> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace.
4.REPLACE VVEL CONTROL MODULE
Replace VVEL control module. Refer to EC-536, "
Removal and Installation".
>> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Select “SELF DIAGNOSTIC RESULT” mode with CONSULT-III.
4. Touch “ERASE”.
5. Perform DTC Confirmation Procedure. See EC-173, "
DTC Logic".
WITH GST
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Select Service $04 with GST.
4. Perform DTC Confirmation Procedure.
See EC-173, "
DTC Logic".
Is the DTC U0113 or U1003 displayed again?
YES >> GO TO 6.
NO >> INSPECTION END
6.REPLACE ECM
Replace ECM. Refer to EC-535, "
Removal and Installation".
>> INSPECTION END
Revision: 2010 May2011 QX56

U1024 CAN COMM CIRCUITEC-175
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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U1024 CAN COMM CIRCUIT
DTC LogicINFOID:0000000006217770
DTC DETECTION LOGIC
NOTE:
If DTC U1024 is displayed with DTC P0607, fi
rst perform the trouble diagnosis for DTC P0607.
Refer to EC-378, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is 10 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 3 seconds.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-175, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217771
1.CHECK VVEL CAN COMMUNICATION CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect VVEL control module harness connector.
4. Check the continuity between ECM harness c onnector and VVEL control module harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and VVEL control module
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
U1024 VVEL CAN COMM CIRCUIT
(VVEL CAN communication)  When VVEL control module cannot transmitting
or receiving CAN communication signal with
ECM for 2 seconds or more.
 When detecting error during the initial diagnosis
of CAN controller of VVEL control module.  Harness or connectors
(CAN communication line is
open or shorted)
ECM
 VVEL control module
ECM VVEL control module Continuity
Connector Terminal Connector Terminal
E80 161
F56 24
Existed
166 11
Revision: 2010 May2011 QX56

EC-176
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
U1024 CAN COMM CIRCUIT
3.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace.
4.REPLACE VVEL CONTROL MODULE
1. Replace VVEL control module.
2. Perform additional service when replac ing VVEL control module. Refer to EC-144, "
Work Procedure".
>> GO TO 5.
5.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Select “SELF DIAGNOSTIC RESULT” mode with CONSULT-III.
4. Touch “ERASE”.
5. Perform DTC Confirmation Procedure.
See EC-175, "
DTC Logic".
WITH GST
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Select Service $04 with GST.
4. Perform DTC Confirmation Procedure.
See EC-175, "
DTC Logic".
Is the DTC U1024 displayed again?
YES >> GO TO 6.
NO >> INSPECTION END
6.REPLACE ECM
1. Replace ECM.
2. Perform additional service when replacing ECM. Refer to EC-143, "
Work Procedure".
>> INSPECTION END
Revision: 2010 May2011 QX56