2008 INFINITI QX56 light

P0441 EVAP CONTROL SYSTEMEC-221
< COMPONENT DIAGNOSIS > [VK56DE]
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With CONSULT-III
1. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port and install vacuum gauge. For the location of EVAP service port, refer to EC-37, "
Description".
2. Start engine and let it idle.
3. Select “PURG VOL CONT/V” in “ACTIVE TEST” mode with CONSULT-III.
4. Rev engine up to 2,000 rpm.
5. Touch “Qd” and “Qu” on CONSULT-III screen to adjust “PURG VOL CONT/V” opening and check vacuum
existence.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
3.CHECK PURGE FLOW
Without CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Stop engine.
3. Disconnect vacuum hose connected to EVAP canister purge volume control solenoid valve at EVAP ser-
vice port and install vacuum gauge. For the location of EVAP service port, refer to EC-37, "
Description".
4. Start engine and let it idle.
Do not depress accelerator pedal even slightly.
5. Check vacuum gauge indication before 60 seconds passed after starting engine.
6. Revving engine up to 2,000 rpm after 100 seconds passed after starting engine.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
4.CHECK EVAP PURGE LINE
1. Turn ignition switch OFF.
2. Check EVAP purge line for improper connection or disconnection. Refer to EC-37, "
Description".
OK or NG
OK >> GO TO 5.
NG >> Repair it.
5.CHECK EVAP PURGE HOSE AND PURGE PORT
1. Disconnect purge hoses connect ed to EVAP service port A and
EVAP canister purge volume control solenoid valve B.
2. Blow air into each hose and EVAP purge port C.
PURG VOL CONT/V Vacuum
100% Should exist.
0% Should not exist.
Vacuum should not exist.
Vacuum should exist.
SEF367U
Revision: March 2010 2008 QX56

P0451 EVAP CONTROL SYSTEM PRESSURE SENSOREC-247
< COMPONENT DIAGNOSIS > [VK56DE]
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P0451 EVAP CONTROL SYST
EM PRESSURE SENSOR
Component DescriptionINFOID:0000000001351610
The EVAP control system pressure sens or detects pressure in the purge line. The sensor output voltage to the
ECM increases as pressure increases.
On Board Diagnosis LogicINFOID:0000000001351612
NOTE:
If DTC P0451 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-293
.
DTC Confirmation ProcedureINFOID:0000000001351613
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.
WITH CONSULT-III
1. Start engine and wait at least 40 seconds. NOTE:
Do not depress accelerator pedal even slightly.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-247, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351614
1.CHECK GROUND CONNECTIONS
BBIA0443E
PBIB1207E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0451
0451 EVAP control system pressure
sensor performance ECM detects a sloshing signal from the
EVAP control system pressure sensor • Harness or connectors
• EVAP control system pressure sensor
Revision: March 2010
2008 QX56

EC-286
< COMPONENT DIAGNOSIS >[VK56DE]
P0550 PSP SENSOR
P0550 PSP SENSOR
Component DescriptionINFOID:0000000001351667
Power steering pressure (PSP) sensor (1) is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
On Board Diagn
osis LogicINFOID:0000000001351669
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P0550 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-293
.
DTC Confirmation ProcedureINFOID:0000000001351670
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.
WITH CONSULT-III
1. Start engine and let it idle for at least 5 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-286, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351672
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection".
OK or NG
BBIA0741E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0550
0550 Power steering pressure
sensor circuit An excessively low or high voltage from the
sensor is sent to ECM. • Harness or connectors
(The sensor circuit is open or shorted)
• Power steering pressure sensor
BBIA0354E
Revision: March 2010 2008 QX56

P0643 SENSOR POWER SUPPLYEC-293
< COMPONENT DIAGNOSIS > [VK56DE]
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P0643 SENSOR POWER SUPPLY
On Board Diagnosis LogicINFOID:0000000001351684
This self-diagnosis has the on
e trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001351685
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 more than 10V at idle.
WITH CONSULT-III
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-293, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351687
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-86, "
Ground Inspection".
OK or NG
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0643
0643 Sensor power supply circuit
short ECM detects a voltage of power source
for sensor is excessively low or high. • Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Battery current sensor circuit is shorted.)
(Refrigerant pressure se nsor circuit is short-
ed.)
(EVAP control system pressure sensor circuit
is shorted.)
• Accelerator pedal position sensor
• Power steering pressure sensor
• Refrigerant pressure sensor
• EVAP control system pressure sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
BBIA0354E
Revision: March 2010 2008 QX56

EC-304
< COMPONENT DIAGNOSIS >[VK56DE]
P1211 TCS CONTROL UNIT
P1211 TCS CONTROL UNIT
DescriptionINFOID:0000000001351704
The malfunction information related to TCS is trans
ferred through the CAN communication line from “ABS
actuator and electric unit (control unit)” to ECM.
Be sure to erase the malfunction information such as DTC not only for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
On Board Diagn osis LogicINFOID:0000000001351705
Freeze frame data is not stored in the ECM for this self-diagnosis.
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000001351706
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-III
1. Start engine and let it idle for at least 60 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-304, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351707
Go to BRC-24, "CONSULT-III Function (ABS)".
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1211
1211 TCS control unit
ECM receives a malfunction information from
“ABS actuator electric
unit (control unit)” • ABS actuator and electric unit (control
unit)
• TCS related parts
Revision: March 2010 2008 QX56

P1212 TCS COMMUNICATION LINEEC-305
< COMPONENT DIAGNOSIS > [VK56DE]
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P1212 TCS COMMUNICATION LINE
DescriptionINFOID:0000000001351708
NOTE:
•
If DTC P1212 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-87
.
• If DTC P1212 is displayed with DTC U1010, first pe rform the trouble diagnosis for DTC U1010. Refer
to EC-88
.
This CAN communication line is used to control the smooth engine operation during the TCS operation. Pulse
signals are exchanged between ECM and “ABS actuator and electric unit (control unit)”.
Be sure to erase the malf unction information such as DTC not onl y for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
On Board Diagnosis LogicINFOID:0000000001351709
Freeze frame data is not stored in the ECM for this self-diagnosis.
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000001351710
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-III
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-305, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351711
Go to BRC-24, "CONSULT-III Function (ABS)".
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1212
1212 TCS communication line ECM can not receive the information from
“ABS actuator and electric unit (control
unit)” continuously. • Harness or connectors
(The CAN communication line is open or short-
ed.)
• ABS actuator and electric unit (control unit)
• Dead (Weak) battery
Revision: March 2010 2008 QX56

EC-310
< COMPONENT DIAGNOSIS >[VK56DE]
P1225 TP SENSOR
P1225 TP SENSOR
Component DescriptionINFOID:0000000001351876
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the
throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagn osis LogicINFOID:0000000001351877
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000001351878
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 more than 10V at idle.
WITH CONSULT-lll
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Check 1st trip DTC.
5. If 1st trip DTC is detected, go to EC-310, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-lll” above.
Diagnosis ProcedureINFOID:0000000001351879
1.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
3. Check if foreign matter is caught between the throttle valve and the housing.
OK or NG
OK >> GO TO 2.
NG >> Remove the foreign matter and clean the electric throttle control actuator inside.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P1225
1225 Closed throttle position learning
performance Closed throttle position learning value is
excessively low. • Electric throttle control actuator
(TP sensor 1 and 2)
BBIA0364E
Revision: March 2010 2008 QX56

EC-312
< COMPONENT DIAGNOSIS >[VK56DE]
P1226 TP SENSOR
P1226 TP SENSOR
Component DescriptionINFOID:0000000001351881
Electric throttle control actuator consists of throttle control motor,
throttle position sensor, etc. The throttle position sensor responds to
the throttle valve movement.
The throttle position sensor has the two sensors. These sensors are
a kind of potentiometers which transform the throttle valve position
into output voltage, and emit the voltage signal to the ECM. In addi-
tion, these sensors detect the opening and closing speed of the
throttle valve and feed the voltage signals to the ECM. The ECM
judges the current opening angle of the
throttle valve from these sig-
nals and the ECM controls the throttle control motor to make the
throttle valve opening angle properly in response to driving condi-
tion.
On Board Diagn osis LogicINFOID:0000000001351882
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000001351883
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 more than 10V at idle.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Repeat steps 2 and 3 for 32 times.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-312, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001351884
1.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Turn ignition switch OFF.
2. Remove the intake air duct.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P1226
1226 Closed throttle position learning
performance Closed throttle position learning is not performed
successfully, repeatedly. • Electric throttle control actuator
(TP sensor 1 and 2)
Revision: March 2010 2008 QX56