2006 INFINITI QX56 ignition

EC-146Revision: November 2009
POWER SUPPLY AND GROUND CIRCUIT
2006 QX56
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.
Diagnostic ProcedureUBS00H0G
1. INSPECTION START
Start engine.
Is engine running?
Ye s o r N o
Yes >> GO TO 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.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
1 B ECM ground [Engine is running]

Idle speed
Body ground
109 L/W Ignition switch [Ignition switch: OFF]
0V
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]

For a few seconds after turning ignition
switch OFF
0 - 1.5V
[Ignition switch: OFF]

More than a few seconds after turning igni-
tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 5
11 6 B
B/W
ECM ground [Engine is running]

Idle speed Body ground
11 9
120 BR
BR
Power supply for ECM
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
Voltage: Battery voltage
MBIB0015E

POWER SUPPLY AND GROUND CIRCUITEC-147
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Revision: November 2009 2006 QX56
4. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-150, "
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-618, "IGNITION SIGNAL" .
NG >> GO TO 8.
BBIA0354E
Continuity should exist.
Voltage: Battery voltage
PBIB2063E

EC-148Revision: November 2009
POWER SUPPLY AND GROUND CIRCUIT
2006 QX56
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.
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. 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 CIRCUITEC-149
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Revision: November 2009 2006 QX56
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.
13. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-150, "
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-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> Replace IPDM E/R.
NG >> Repair open circuit or short to power in harness or connectors.
BBIA0354E
Continuity should exist.

DTC U1000, U1001 CAN COMMUNICATION LINEEC-151
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Revision: November 2009 2006 QX56
DTC U1000, U1001 CAN COMMUNICATION LINEPFP:23710
DescriptionUBS00H0I
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
On Board Diagnosis LogicUBS00H0J
*1: This self-diagnosis has the one trip detection logic.
*2: The MIL will not light up for this diagnosis.
DTC Confirmation ProcedureUBS00H0K
1. Turn ignition switch ON and wait at least 3 seconds.
2. Select “DATA MONITOR ” mode with CONSULT-II.
3. If 1st trip DTC is detected, go to EC-153, "
Diagnostic Procedure" .
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
U1000*
1
1000*1
CAN communication line

ECM cannot communicate to other control
units.

ECM cannot communicate for more than the
specified time.

Harness or connectors
(CAN communication line is open or
shorted)
U1001*
2
1001*2

EC-154Revision: November 2009
DTC U1010 CAN COMMUNICATION
2006 QX56
DTC U1010 CAN COMMUNICATIONPFP:23710
DescriptionUBS00N8U
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
On Board Diagnosis LogicUBS00N8V
This self-diagnosis has the one trip detection logic.
DTC Confirmation ProcedureUBS00N8W
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR ” mode with CONSULT-II.
3. If DTC is detected, go to EC-155, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
U1010
1010 CAN communication bus Initializing CAN communication bus is mal-
functioning.

ECM
SEF058Y

DTC U1010 CAN COMMUNICATIONEC-155
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Revision: November 2009 2006 QX56
Diagnostic ProcedureUBS00N8X
1. INSPECTION START
With CONSULT-II
1. Turn ignition switch ON.
2. Select “SELF-DIAG RESULTS ” mode with CONSULT-II.
3. Touch “ERASE”.
4. Perform DTC Confirmation Procedure.
See EC-154, "
DTC Confirmation Procedure" .
5. Is the DTC U1010 displayed again?
With GST
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Perform DTC Confirmation Procedure.
See EC-154, "
DTC Confirmation Procedure" .
4. Is the DTC U1010 displayed again?
Ye s o r N o
Ye s > > G O T O 2 .
No >> INSPECTION END
2. REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to BL-139, "
ECM Re-communicating Function" .
3. Perform EC-77, "
VIN Registration" .
4. Perform EC-78, "
Accelerator Pedal Released Position Learning" .
5. Perform EC-78, "
Throttle Valve Closed Position Learning" .
6. Perform EC-78, "
Idle Air Volume Learning" .
>> INSPECTION END

EC-156Revision: November 2009
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
2006 QX56
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATERPFP:22693
DescriptionUBS00H71
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
CONSULT-II Reference Value in Data Monitor ModeUBS00H72
Specification data are reference values.
On Board Diagnosis LogicUBS00H73
DTC Confirmation ProcedureUBS00H74
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and let it idle for at least 10 seconds.
3. If 1st trip DTC is detected, go to EC-160, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Sensor Input Signal to ECM ECM functionActuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Air fuel ratio (A/F) sensor 1
heater controlAir fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITIONSPECIFICATION
A/F S1 HTR (B1)
A/F S1 HTR (B2)

Engine: After warming up, idle the engine 0 - 100%
DTC No. Trouble diagnosis nameDTC detecting conditionPossible cause
P0031
0031
(Bank 1) Air fuel ratio (A/F) sensor
1 heater control circuit
low The current amperage in the air fuel ratio (A/F)
sensor 1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)

Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)

A/F sensor 1 heater
P0051
0051
(Bank 2)
P0032
0032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
high The current amperage in the air fuel ratio (A/F)
sensor 1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)

Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)

A/F sensor 1 heater
P0052
0052
(Bank 2)
SEF058Y