2008 INFINITI QX56 ignition

EC-368
< COMPONENT DIAGNOSIS >[VK56DE]
P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
P2119 ELECTRIC THROTTLE CONTROL ACTUATOR
Component DescriptionINFOID:0000000001528873
Electric throttle control actuator consists of th
rottle 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 va lve 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 thrott le control motor to make the throttle valve opening
angle properly in response to driving condition.
On Board Diagn osis LogicINFOID:0000000001528874
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:0000000001528875
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-III
1. Turn ignition switch ON and wait at least 1 second.
2. Shift selector lever to D position and wait at least 3 seconds.
3. Shift selector lever to P or N position.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Turn ignition switch ON and wait at least 1 second.
6. Shift selector lever to D position and wait at least 3 seconds.
7. Shift selector lever to P or N position.
8. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
9. Check DTC.
10. If DTC is detected, go to EC-369, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-III” above.
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P2119
2119 Electric throttle control
actuator A)
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 A The 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 C While 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.
Revision: March 2010
2008 QX56

P2119 ELECTRIC THROTTLE CONTROL ACTUATOREC-369
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
PROCEDURE FOR MALFUNCTION C
With CONSULT-III
1. Turn ignition switch ON and wait at least 1 second.
2. Shift selector lever to D position and wait at least 3 seconds.
3. Shift selector lever to P position.
4. Start engine and let it idle for 3 seconds.
5. Check DTC.
6. If DTC is detected, go to EC-369, "
Diagnosis Procedure".
With GST
Follow the procedure “With CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001528876
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-18, "
Throttle Valve Closed Position Learning".
3. Perform EC-18, "
Idle Air Volume Learning".
>> INSPECTION END
BBIA0364E
Revision: March 2010 2008 QX56

EC-370
< COMPONENT DIAGNOSIS >[VK56DE]
P2122, P2123 APP SENSOR
P2122, P2123 APP SENSOR
Component DescriptionINFOID:0000000001365823
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.
On Board Diagn
osis LogicINFOID:0000000001365825
These self-diagnoses have the one trip detection logic.
NOTE:
If DTC P2122 or P2123 is displayed with DTC P0643, first perform the tro\
ubl e diagnosis for DTC P0643.
Refer to EC-293
.
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:0000000001365826
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 8V at idle.
WITH CONSULT-IIl
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-371, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-lII” above.
PBIB1741E
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P2122
2122 Accelerator pedal position
sensor 1 circuit low input An excessively low vo
ltage 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
2123
Accelerator pedal position
sensor 1 circuit high input An excessively high vo
ltage 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.
Revision: March 2010 2008 QX56

P2122, P2123 APP SENSOREC-371
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Diagnosis ProcedureINFOID:0000000001365828
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
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK APP SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 7 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
3.CHECK APP SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 82 and APP sensor terminal 1. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
BBIA0354E
BBIA0361E
Voltage: Approximately 5V
JMBIA0601ZZ
Continuity should exist.
Revision: March 2010 2008 QX56

EC-372
< COMPONENT DIAGNOSIS >[VK56DE]
P2122, P2123 APP SENSOR
4.CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 106 and APP sensor terminal 2. Refer to Wiring Diagram.
2. 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 APP SENSOR
Refer to EC-372, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-18, "
Accelerator Pedal Released Position Learning".
3. Perform EC-18, "
Throttle Valve Closed Position Learning".
4. Perform EC-18, "
Idle Air Volume Learning".
>> INSPECTION END
7.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001365829
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 106 (APP sensor 1 sig-
nal), 98 (APP sensor 2 signal) and ground under the following
conditions.
4. If NG, replace accelerator pedal assembly and go to next step.
5. Perform EC-18, "
Accelerator Pedal Released Position Learning".
6. Perform EC-18, "
Throttle Valve Closed Position Learning".
7. Perform EC-18, "
Idle Air Volume Learning".
Continuity should exist.
Terminal
Accelerator pedal Voltage
106
(Accelerator pedal position
sensor 1) Fully released
0.5 - 1.0V
Fully depressed 4.2 - 4.8V
98
(Accelerator pedal position
sensor 2) Fully released
0.25 - 0.5V
Fully depressed 2.0 - 2.5V
MBIB0023E
Revision: March 2010 2008 QX56

P2127, P2128 APP SENSOREC-373
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P2127, P2128 APP SENSOR
Component DescriptionINFOID:0000000001365832
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 accelerato
r 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.
On Board Diagnosis LogicINFOID:0000000001365834
These self-diagnoses have 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:0000000001365835
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 8V at idle.
WITH CONSULT-IIl
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-373, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-lII” above.
Diagnosis ProcedureINFOID:0000000001365837
1.CHECK GROUND CONNECTIONS
PBIB1741E
DTC No. Trouble diagnosis nameDTC detecting conditionPossible cause
P2127
2127 Accelerator pedal position
sensor 2 circuit low input An excessively low voltage from the APP
sensor 2 is sent to ECM. • Harness or connectors
(APP sensor 2 circuit is open or shorted.)
(TP sensor circuit is shorted.)
• Accelerator pedal position sensor (Accelerator pedal position sensor 2)
• Electric throttle control actuator (TP sensor)
P2128
2128
Accelerator pedal position
sensor 2 circuit high input An excessively high
voltage from the APP
sensor 2 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.
Revision: March 2010 2008 QX56

EC-374
< COMPONENT DIAGNOSIS >[VK56DE]
P2127, P2128 APP SENSOR
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-86, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-I
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 6 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between APP sensor terminal 6 and ECM terminal 91. Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit.
4.CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals
BBIA0354E
BBIA0361E
Voltage: Approximately 5V
JMBIA0602ZZ
Continuity should exist.
Revision: March 2010 2008 QX56

P2127, P2128 APP SENSOREC-375
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5.CHECK THROTTLE
POSITION SENSOR
Refer to EC-380, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> GO TO 6.
6.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
1. Replace the electric throttle control actuator.
2. Perform EC-18, "
Throttle Valve Closed Position Learning".
3. Perform EC-18, "
Idle Air Volume Learning".
>> INSPECTION END
7.CHECK APP SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 83 and APP sensor terminal 3. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK APP SENSOR 2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 98 and APP sensor terminal 5. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK APP SENSOR
Refer to EC-376, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace the accelerator pedal assembly.
2. Perform EC-18, "
Accelerator Pedal Released Position Learning".
3. Perform EC-18, "
Throttle Valve Closed Position Learning".
4. Perform EC-18, "
Idle Air Volume Learning".
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2
EC-439, "
Wiring Diagram - ENGINE
CONTROL SYSTEM -"91APP sensor terminal 6
Continuity should exist.
Continuity should exist.
Revision: March 2010 2008 QX56