air condition INFINITI QX56 2007 Factory Service Manual

DTC P1140, P1145 IVT CONTROL POSITION SENSOR
EC-461
< SERVICE INFORMATION >
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000003531977
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK INTAKE VALVE TIMING CONTROL POSITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect intake valve timing control position sensor harness connector.
TER-
MI-
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NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
53 LIntake valve timing control
position sensor (Bank 2)[Engine is running]
•Warm-up condition
• Idle speed0 - 1.0V
[Engine is running]
• Engine speed: 2,000 rpm0 - 1.0V
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 9
120BR
BRPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
PBIB2046E
BBIA0354E

EC-466
< SERVICE INFORMATION >
DTC P1148, P1168 CLOSED LOOP CONTROL
DTC P1148, P1168 CLOSED LOOP CONTROL
On Board Diagnosis LogicINFOID:0000000003531980
These self-diagnoses have the one 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
functionThe 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.

DTC P1211 TCS CONTROL UNIT
EC-467
< SERVICE INFORMATION >
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DTC P1211 TCS CONTROL UNIT
DescriptionINFOID:0000000003531981
The malfunction information related to TCS is transferred 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 Diagnosis LogicINFOID:0000000003531982
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:0000000003531983
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 60 seconds.
4. If 1st trip DTC is detected, go to EC-467, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003531984
Go to BRC-11.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1211
1211TCS control unitECM receives a malfunction information from
“ABS actuator electric unit (control unit)”• ABS actuator and electric unit (control
unit)
• TCS related parts
SEF058Y

EC-468
< SERVICE INFORMATION >
DTC P1212 TCS COMMUNICATION LINE
DTC P1212 TCS COMMUNICATION LINE
DescriptionINFOID:0000000003531985
NOTE:
•If DTC P1212 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-145
.
•If DTC P1212 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer
to EC-147
.
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 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 Diagnosis LogicINFOID:0000000003531986
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:0000000003531987
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for at least 10 seconds.
4. If 1st trip DTC is detected, go to EC-468, "
Diagnosis Procedure"
.
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003531988
Go to BRC-11.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1212
1212TCS communication lineECM 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
SEF058Y

DTC P1217 ENGINE OVER TEMPERATURE
EC-469
< SERVICE INFORMATION >
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DTC P1217 ENGINE OVER TEMPERATURE
DescriptionINFOID:0000000003531989
SYSTEM DESCRIPTION
NOTE:
•If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC
U1000, U1001. Refer to EC-145
.
•If DTC P1217 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer
to EC-147
.
Cooling Fan Control
*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM through CAN communication line.
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant
pressure, and air conditioner ON signal. The control system has 2-step control [HI/OFF].
Cooling Fan Operation
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531990
Specification data are reference values.
Sensor Input signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
1
Cooling fan
controlIPDM E/R
(Cooling fan relay) Battery
Battery voltage*
1
Wheel sensor
Vehicle speed*2
Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch
Air conditioner ON signal*
2
Refrigerant pressure sensor Refrigerant pressure
PBIB2060E
MONITOR ITEM CONDITION SPECIFICATION
AIR COND SIG• Engine: After warming up, idle the
engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON

DTC P1225 TP SENSOR
EC-477
< SERVICE INFORMATION >
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DTC P1225 TP SENSOR
Component DescriptionINFOID:0000000003531997
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 Diagnosis LogicINFOID:0000000003531998
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000003531999
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-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. If 1st trip DTC is detected, go to EC-477, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003532000
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 condition Possible cause
P1225
1225Closed throttle position learning
performanceClosed throttle position learning value is
excessively low.• Electric throttle control actuator
(TP sensor 1 and 2)
SEF058Y

DTC P1226 TP SENSOR
EC-479
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DTC P1226 TP SENSOR
Component DescriptionINFOID:0000000003532002
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 Diagnosis LogicINFOID:0000000003532003
The MIL will not light up for this self-diagnosis.
DTC Confirmation ProcedureINFOID:0000000003532004
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-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON.
5. Repeat steps 3 and 4 for 32 times.
6. If 1st trip DTC is detected, go to EC-479, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003532005
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 condition Possible cause
P1226
1226Closed throttle position learning
performanceClosed throttle position learning is not performed
successfully, repeatedly.• Electric throttle control actuator
(TP sensor 1 and 2)
SEF058Y

DTC P1421 COLD START CONTROL
EC-481
< SERVICE INFORMATION >
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DTC P1421 COLD START CONTROL
DescriptionINFOID:0000000003532007
ECM controls ignition timing and engine idle speed when engine is started with prewarming up condition.
This control promotes the activation of three way catalyst by heating the catalyst and reduces emissions.
On Board Diagnosis LogicINFOID:0000000003532008
DTC Confirmation ProcedureINFOID:0000000003532009
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.
•If DTC P1421 is displayed with other DTC, first perform the trouble diagnosis for other DTC.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Check that the “COOLAN TEMP/S” indication is between 4°C
(39°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 specified value,
cool engine down or warm engine up and go to step 1.
5. Start engine and let it idle for 5 minutes.
6. If 1st trip DTC is detected, go to EC-481, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003532010
1.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-78, "
Idle Air Volume Learning".
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 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 condition Possible cause
P1421
1421Cold start emission reduction
strategy monitoringECM does not control ignition timing and engine
idle speed properly when engine is started with
prewarming up condition.• Lack of intake air volume
• Fuel injection system
•ECM
SEF174Y

DTC P1550 BATTERY CURRENT SENSOR
EC-483
< SERVICE INFORMATION >
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DTC P1550 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000003532011
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 SC section.
CAUTION:
Do not connect the electrical component or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of the power generation voltage variable control, and then the battery
discharge may occur.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532012
Specification data are reference values.
*: Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to SC-4, "How to Handle Battery".
On Board Diagnosis LogicINFOID:0000000003532013
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-447
.
DTC Confirmation ProcedureINFOID:0000000003532014
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 8V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
BBIA0744E
MONITOR ITEM CONDITION SPECIFICATION
BAT CUR SEN• Engine speed: Idle
• Battery: Fully charged*
• Selector lever: P or N
• Air conditioner switch: OFF
•No loadApprox. 2,600 - 3,500mV
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1550
1550Battery current sensor circuit
range/performanceThe 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

EC-486
< SERVICE INFORMATION >
DTC P1550 BATTERY CURRENT SENSOR
*: Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to SC-4, "How to Handle Battery".
Diagnosis ProcedureINFOID:0000000003532016
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to EC-143, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK BATTERY CURRENT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect battery current sensor (1) harness connector.
2. Turn ignition switch ON.
TER-
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NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
49 R/YSensor power supply
(Battery current sensor)[Ignition switch: ON]Approximately 5V
67 BSensor ground
(Battery current sensor)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
71 R Battery current sensor[Engine is running]
• Battery: Fully charged*
• Idle speedApproximately 2.6 - 3.5V
BBIA0354E
BBIA0744E