2010 INFINITI QX56 fuel

EC-276
< COMPONENT DIAGNOSIS >[VK56DE]
P0500 VSS
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to
EC-276, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000005149301
Use this procedure to check the overall function of the vehicle speed signal circuit. During this check, a 1st trip
DTC might not be confirmed.
WITH GST
1. Lift up drive wheels.
2. Start engine.
3. Read vehicle speed signal in Service $01 with GST.
The vehicle speed signal on GST should be able to exceed 10 km/h (6 MPH) when rotating wheels with
suitable gear position.
4. If NG, go to EC-276, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149302
1.CHECK DTC WITH ABS ACTUATOR AN D ELECTRIC UNIT (CONTROL UNIT)
Refer to BRC-23, "
CONSULT-III Function (ABS)".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace.
2.CHECK COMBINATION METER FUNCTION
Refer to MWI-5
.
>> INSPECTION END
B/FUEL SCHDL 6.9 - 31.8 msec
Selector lever Except P or N position
PW/ST SIGNAL OFF
Revision: April 20092010 QX56

EC-284
< COMPONENT DIAGNOSIS >[VK56DE]
P0603 ECM POWER SUPPLY
P0603 ECM POWER SUPPLY
Component DescriptionINFOID:0000000005149316
Battery voltage is supplied to the ECM even when the ignition switch
is turned OFF for the ECM memory function of the DTC memory, the
air-fuel ratio feedback compensation value memory, the idle air vol-
ume learning value memory, etc.
On Board Diagn
osis LogicINFOID:0000000005149317
DTC Confirmation ProcedureINFOID:0000000005149318
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and let it idle for 1 second.
3. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
4. Repeat steps 1 and 2 for 4 times.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-284, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149319
1.CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check voltage between ECM terminal 121 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0603
0603 ECM power supply circuit ECM back-up RAM system does not function
properly. • Harness or connectors
[ECM power supply (b ack-up) circuit is
open or shorted.]
•ECM
Voltage: Battery voltage
MBIB0026E
Revision: April 20092010 QX56

EC-292
< COMPONENT DIAGNOSIS >[VK56DE]
P0850 PNP SWITCH
P0850 PNP SWITCH
Component DescriptionINFOID:0000000005149331
When the selector lever position is P or N, park/neutral position (PNP) signal from the TCM is sent to ECM.
When the gear position is P or N, transmission range switch is ON.
On Board Diagn
osis LogicINFOID:0000000005149332
DTC Confirmation ProcedureINFOID:0000000005149333
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode with CONSULT-III. Then check the “P/N POSI SW” sig-
nal under the following conditions.
If NG, go to EC-293, "
Diagnosis Procedure".
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-293, "
Diagnosis Procedure".
Overall Function CheckINFOID:0000000005149334
Use this procedure to check the overall function of t he park/neutral position (PNP) signal circuit. During this
check, a 1st trip DTC might not be confirmed.
WITH GST
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0850
0850 Park/neutral position
switch The signal of the park/neutral position (PNP)
signal is not changed in the process of engine
starting and driving. • Harness or connectors
[The park/neutral position (PNP) signal
circuit is open or shorted.]
• Combination meter
•TCM
Position (Selector lever) Known-good signal
N or P position ON
Except the above position OFF
ENG SPEED1,000 - 6,375 rpm
COOLAN TEMP/S More than 70°C (158 °F)
B/FUEL SCHDL 2.0 - 31.8 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
Revision: April 20092010 QX56

P1148, P1168 CLOSED LOOP CONTROLEC-299
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P1148, P1168 CLOSED LOOP CONTROL
On Board Diagnosis LogicINFOID:0000000005149341
These self-diagnoses have the on
e trip detection logic.
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1148
11 4 8
(Bank 1) Closed loop control
function The closed loop control function for bank 1 does
not operate even when vehicle is driving in the
specified condition.
• Harness or connectors
[The air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]
• Air fuel ratio (A/F) sensor 1
• Air fuel ratio (A/F) sensor 1 heater
P1168
11 6 8
(Bank 2) The closed loop control function for bank 2 does
not operate even when vehicle is driving in the
specified condition.
Revision: April 20092010 QX56

EC-310
< COMPONENT DIAGNOSIS >[VK56DE]
P1421 COLD START CONTROL
P1421 COLD START CONTROL
DescriptionINFOID:0000000005149362
ECM controls ignition timing and engine idle speed when engine is started with pre-warming up condition.
This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.
On Board Diagn
osis LogicINFOID:0000000005149363
If DTC P1421 is displayed with ot her DTC, first perform the trouble diagnosis for other DTC.
DTC Confirmation ProcedureINFOID:0000000005149364
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11 V at idle.
WITH CONSULT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Check that the “COOLAN TEMP/S” indication is between 5 °C (41° F) and 36 °C (97° F).
If “COOLAN TEMP/S” indication is within the specified value, go to the following step.
If “COOLANT TEMP/S” indication is out of the s pecified value, cool engine down or warm engine up and
go to step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-310, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000005149365
1.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-18, "
Idle Air Volume Learning".
Is Idle Air Volume Lear ning carried out successfully?
Ye s o r N o
Ye s > > G O T O 2 .
No >> Follow the instruction of Idle Air Volume Learning.
2.CHECK INTAKE SYSTEM
Check for the cause of intake air volume lacking. Refer to the following.
• Crushed intake air passage
• Intake air passage clogging
OK or NG
OK >> GO TO 3.
NG >> Repair or replace malfunctioning part
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P1421
1421 Cold start emission reduction
strategy monitoring ECM does not control ignition timing and engine
idle speed properly when engine is started with
pre-warming up condition. • Lack of intake air volume
• Fuel injection system
•ECM
Revision: April 20092010 QX56

P1421 COLD START CONTROLEC-311
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
3.CHECK FUEL INJECTION SYSTEM FUNCTION
Perform EC-172, "
DTC Confirmation Procedure" in DTC P0171, P0174 FUEL INJECTION SYSTEM FUNC-
TION.
OK or NG
OK >> GO TO 4.
NG >> Go to EC-173, "
Diagnosis Procedure".
4.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Turn ignition switch ON.
2. Select “SELF DIAG RESULTS” mode with CONSULT-III.
3. Touch “ERASE”.
4. Perform DTC Confirmation Procedure.
See EC-310, "
DTC Confirmation Procedure".
5. Is the 1st trip DTC P1421 displayed again?
With GST
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Perform DTC Confirmation Procedure.
See EC-310, "
DTC Confirmation Procedure".
4. Is the 1st trip DTC P1421 displayed again?
Ye s o r N o
Yes >> GO TO 5.
No >> INSPECTION END
5.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs.
Refer to SEC-9, "
ECM RE-COMMUNICATING FUNCTION : Special Repair Requirement".
3. Perform EC-17, "
VIN Registration".
4. Perform EC-18, "
Accelerator Pedal Released Position Learning".
5. Perform EC-18, "
Throttle Valve Closed Position Learning".
6. Perform EC-18, "
Idle Air Volume Learning".
>> INSPECTION END
Revision: April 20092010 QX56

EC-312
< COMPONENT DIAGNOSIS >[VK56DE]
P1550 BATTERY CURRENT SENSOR
P1550 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000005149366
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator. The battery cur-
rent sensor (1) is installed to the battery cable at the negative termi-
nal. The sensor measures the charging/discharging current of the
battery. Based on the sensor signal, ECM judges whether or not the
power generation voltage variable control is performed. When per-
forming the power generation voltage variable control, ECM calcu-
lates the target power generation voltage based on the sensor
signal. And ECM sends the calculated value as the power genera-
tion command value to IPDM E/R. For the details of the power gen-
eration voltage variable control, refer to
CHG-7, "
System
Description".
: Vehicle front
CAUTION:
Do not connect the electrical compon ent or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
On Board Diagn osis LogicINFOID:0000000005149367
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1550 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-289
.
DTC Confirmation ProcedureINFOID:0000000005149368
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8 V at idle.
1. Start engine and wait at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-312, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149369
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
BBIA0744E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P1550
1550 Battery current sensor circuit
range/performance The output voltage of the battery current
sensor remains within the specified
range while engine is running. • Harness or connectors
(The sensor circuit is open or shorted.)
• Battery current sensor
Revision: April 20092010 QX56

EC-316
< COMPONENT DIAGNOSIS >[VK56DE]
P1551, P1552 BATTERY CURRENT SENSOR
P1551, P1552 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000005149371
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator. The battery cur-
rent sensor (1) is installed to the battery cable at the negative termi-
nal. The sensor measures the charging/discharging current of the
battery. Based on the sensor signal, ECM judges whether or not the
power generation voltage variable control is performed. When per-
forming the power generation voltage variable control, ECM calcu-
lates the target power generation voltage based on the sensor
signal. And ECM sends the calculated value as the power genera-
tion command value to IPDM E/R. For the details of the power gen-
eration voltage variable control, refer to
CHG-7, "
System
Description".
: Vehicle front
CAUTION:
Do not connect the electrical compon ent or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
On Board Diagn osis LogicINFOID:0000000005149372
The MIL will not light up for these self-diagnoses.
NOTE:
If DTC P1551 or P1552 is displayed with DTC P0643, first perform the tro\
ubl e diagnosis for DTC P0643.
Refer to EC-289, "
On Board Diagnosis Logic".
DTC Confirmation ProcedureINFOID:0000000005149373
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next step.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following pro cedure, confirm that battery voltage is more than 8 V with ignition
switch ON
1. Turn ignition switch ON.
2. Wait at least 10 seconds.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-316, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000005149374
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
BBIA0744E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P1551
1551 Battery current sensor circuit
low input An excessively low voltage from the sensor
is sent to ECM.
• Harness or connectors
(The sensor circuit is open or shorted.)
• Battery current sensor
P1552
1552 Battery current sensor circuit
high input An excessively high voltage from the sensor
is sent to ECM.
Revision: April 20092010 QX56