ignition INFINITI QX56 2007 Factory Service Manual

EC-550
< SERVICE INFORMATION >
DTC P2101 ELECTRIC THROTTLE CONTROL FUNCTION
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000003532095
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 THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-I
TER-
MI-
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NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4L/WThrottle control motor
(Close)[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Released0 - 14V
5L/BThrottle control motor
(Open)[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully depressed0 - 14V
104 O Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
PBIB1104E
PBIB1105E
BBIA0354E

DTC P2101 ELECTRIC THROTTLE CONTROL FUNCTION
EC-551
< SERVICE INFORMATION >
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1. Check voltage between ECM terminal 3 and ground under the
following conditions with CONSULT-II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 3.
3.CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-I
1. Turn ignition switch OFF.
2. Check voltage between ECM terminal 104 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 4.
4.CHECK THROTTLE CONTROL MOTOR RELAY POWER SUPPLY CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E122.
3. Check harness continuity between ECM terminal 104 and IPDM E/R terminal 47.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK FUSE
1. Disconnect 20A fuse.
2. Check 20A fuse for blown.
OK or NG
OK >> GO TO 8.
NG >> Replace 20A fuse.
6.CHECK THROTTLE CONTROL MOTOR RELAY INPUT SIGNAL CIRCUIT-II
1. Disconnect ECM harness connector.
2. Disconnect IPDM E/R harness connector E119.
3. Check harness continuity between ECM terminal 3 and IPDM E/R terminal 6.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
Ignition switch Voltage
OFF Approximately 0V
ONBattery voltage
(11 - 14V)
MBIB0028E
Voltage: Battery voltage
PBIB1171E
Continuity should exist.
Continuity should exist.

EC-552
< SERVICE INFORMATION >
DTC P2101 ELECTRIC THROTTLE CONTROL FUNCTION
7.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E2, F32
• Harness for open or short between ECM and IPDM E/R
>> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
OK or NG
OK >> Replace IPDM E/R. Refer to PG-28, "Removal and Installation of IPDM E/R".
NG >> Repair or replace harness or connectors.
9.CHECK THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Turn ignition switch OFF.
2. Disconnect electric throttle control actuator harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between the following terminals.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair or replace.
10.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Remove the intake air duct.
2. Check if foreign matter is caught between the throttle valve and
the housing.
OK or NG
OK >> GO TO 11.
NG >> Remove the foreign matter and clean the electric throttle
control actuator inside.
11 .CHECK THROTTLE CONTROL MOTOR
Refer to EC-553, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 13.
12.CHECK INTERMITTENT INCIDENT
Refer to EC-138
.
OK or NG
OK >> GO TO 13.
Electric throttle control
actuator terminalECM terminal Continuity
55 Should not exist
4 Should exist
65 Should exist
4 Should not exist
PBIB1480E
BBIA0364E

EC-554
< SERVICE INFORMATION >
DTC P2118 THROTTLE CONTROL MOTOR
DTC P2118 THROTTLE CONTROL MOTOR
Component DescriptionINFOID:0000000003532098
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The current opening angle of the throttle valve is detected by the throttle position sensor and it provides feed-
back to the ECM to control the throttle control motor to make the throttle valve opening angle properly in
response to driving condition.
On Board Diagnosis LogicINFOID:0000000003532099
This self-diagnosis has the one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003532100
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-II
1. Turn ignition switch ON and wait at least 2 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 5 seconds.
4. If DTC is detected, go to EC-556, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2118
2118Throttle control motor
circuit shortECM detects short in both circuits between
ECM and throttle control motor.• Harness or connectors
(Throttle control motor circuit is shorted.)
• Electric throttle control actuator
(Throttle control motor)
Engine operating condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF058Y

EC-556
< SERVICE INFORMATION >
DTC P2118 THROTTLE CONTROL MOTOR
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000003532102
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 THROTTLE CONTROL MOTOR OUTPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4L/WThrottle control motor
(Close)[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully released0 - 14V
5L/BThrottle control motor
(Open)[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully depressed0 - 14V
104 O Throttle control motor relay[Ignition switch: OFF]BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON]0 - 1.0V
PBIB1104E
PBIB1105E
BBIA0354E

DTC P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
EC-559
< SERVICE INFORMATION >
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DTC P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
Component DescriptionINFOID:0000000003532105
Electric throttle control actuator consists of throttle control motor, throttle position sensor, etc.
The throttle control motor is operated by the ECM and it opens and closes the throttle valve.
The throttle position sensor detects the throttle valve position, and the opening and closing speed of the throt-
tle valve and feeds the voltage signals to the ECM. The ECM judges the current opening angle of the throttle
valve from these signals and the ECM controls the throttle control motor to make the throttle valve opening
angle properly in response to driving condition.
On Board Diagnosis LogicINFOID:0000000003532106
This self-diagnosis has one trip detection logic.
FA I L - S A F E M O D E
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003532107
NOTE:
•Perform PROCEDURE FOR MALFUNCTION A AND B first. If the DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION C.
• If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR MALFUNCTION A AND B
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Shift selector lever to D position and wait at least 3 seconds.
4. Shift selector lever to P or N position.
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Turn ignition switch ON and wait at least 1 second.
7. Shift selector lever to D position and wait at least 3 seconds.
8. Shift selector lever to P or N position.
9. Turn ignition switch OFF, wait at least 10 seconds and then turn
ON.
10. If DTC is detected, go to EC-560, "
Diagnosis Procedure".
With GST
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2119
2119Electric throttle control
actuatorA)Electric throttle control actuator does not func-
tion properly due to the return spring malfunc-
tion.
• Electric throttle control actuator
B)Throttle valve opening angle in fail-safe mode is
not in specified range.
C) ECM detect the throttle valve is stuck open.
Detected items Engine operating condition in fail-safe mode
Malfunction AThe ECM controls the electric throttle actuator by regulating the throttle opening around the idle position.
The engine speed will not rise more than 2,000 rpm.
Malfunction B ECM controls the electric throttle control actuator by regulating the throttle opening to 20 degrees or less.
Malfunction CWhile the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or more.
SEF058Y

EC-560
< SERVICE INFORMATION >
DTC P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION C
With CONSULT-II
1. Turn ignition switch ON and wait at least 1 second.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Shift selector lever to D position and wait at least 3 seconds.
4. Shift selector lever to P position.
5. Start engine and let it idle for 3 seconds.
6. If DTC is detected, go to EC-560, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-II” above.
Diagnosis ProcedureINFOID:0000000003532108
1.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR VISUALLY
1. Remove the intake air duct.
2. Check if a 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.
2.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-77, "
Throttle Valve Closed Position Learning".
3. Perform EC-78, "
Idle Air Volume Learning".
>>INSPECTION END
SEF058Y
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DTC P2122, P2123 APP SENSOR
EC-561
< SERVICE INFORMATION >
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DTC P2122, P2123 APP SENSOR
Component DescriptionINFOID:0000000003532109
The accelerator pedal position sensor is installed on the upper end
of the accelerator pedal assembly. The sensor detects the accelera-
tor position and sends a signal to the ECM.
Accelerator pedal position sensor has two sensors. These sensors
are a kind of potentiometers which transform the accelerator pedal
position into output voltage, and emit the voltage signal to the ECM.
In addition, these sensors detect the opening and closing speed of
the accelerator pedal and feed the voltage signals to the ECM. The
ECM judges the current opening angle of the accelerator pedal from
these signals and controls the throttle control motor based on these
signals.
Idle position of the accelerator pedal is determined by the ECM
receiving the signal from the accelerator pedal position sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003532110
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminal voltage.
On Board Diagnosis LogicINFOID:0000000003532111
These self-diagnoses have the one trip detection logic.
NOTE:
If DTC P2122 or P2123 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to EC-447
.
FA I L - S A F E M O D E
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003532112
NOTE:
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN 1• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
ACCEL SEN 2*• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.2 - 4.8V
CLSD THL POS• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2122
2122Accelerator pedal position
sensor 1 circuit low inputAn excessively low voltage from the APP sen-
sor 1 is sent to ECM.• Harness or connectors
(The APP sensor 1 circuit is open or
shorted.)
• Accelerator pedal position sensor
(Accelerator pedal position sensor 1) P2123
2123Accelerator pedal position
sensor 1 circuit high inputAn excessively high voltage from the APP sen-
sor 1 is sent to ECM.
Engine operating condition in fail-safe mode
The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle position to be within +10
degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor.

EC-562
< SERVICE INFORMATION >
DTC P2122, P2123 APP SENSOR
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.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-564, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF058Y

EC-564
< SERVICE INFORMATION >
DTC P2122, P2123 APP SENSOR
Diagnosis Procedure
INFOID:0000000003532114
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 APP SENSOR 1 POWER SUPPLY CIRCUIT
TER-
MI-
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NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
82 B/RSensor ground
(APP sensor 1)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
83 G/WSensor ground
(APP sensor 2)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
90 LSensor power supply
(APP sensor 1)[Ignition switch: ON]Approximately 5V
91 W/RSensor power supply
(APP sensor 2)[Ignition switch: ON]Approximately 5V
98 G/RAccelerator pedal position
sensor 2[Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully released0.25 - 0.50V
[Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully depressed2.0 - 2.5V
106 BR/WAccelerator pedal position
sensor 1[Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully released0.5 - 1.0V
[Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully depressed4.2 - 4.8V
BBIA0354E