2009 INFINITI QX56 ignition

EC-364
< COMPONENT DIAGNOSIS >[VK56DE]
P2122, P2123 APP SENSOR
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-364, "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:0000000003771683
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: December 20092009 QX56

P2127, P2128 APP SENSOREC-365
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P2127, P2128 APP SENSOR
Component DescriptionINFOID:0000000003771684
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 positi on sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
On Board Diagnosis LogicINFOID:0000000003771685
These self-diagnoses have the on e trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003771686
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-365, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771687
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
PBIB1741E
DTC No. Trouble diagnosis name DTC detecting condition Possible 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: December 20092009 QX56

EC-366
< COMPONENT DIAGNOSIS >[VK56DE]
P2127, P2128 APP SENSOR
Refer to
EC-85, "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.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-432, "Wiring Diagram - ENGINE
CONTROL SYSTEM -"91 APP sensor terminal 6
Revision: December 20092009 QX56

P2127, P2128 APP SENSOREC-367
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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-372, "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-368, "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"
.
>> INSPECTION END
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
Continuity should exist.
Continuity should exist.
Revision: December 20092009 QX56

EC-368
< COMPONENT DIAGNOSIS >[VK56DE]
P2127, P2128 APP SENSOR
>>
INSPECTION END
Component InspectionINFOID:0000000003771688
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"
.
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: December 20092009 QX56

P2135 TP SENSOREC-369
< COMPONENT DIAGNOSIS > [VK56DE]
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P2135 TP SENSOR
Component DescriptionINFOID:0000000003771689
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 t he 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 t he 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:0000000003771690
This self-diagnosis has the on e trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003771691
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-369, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771692
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P2135
2135 Throttle position sensor
circuit range/performance Rationally incorrect voltage is sent to ECM
compared with the signals from TP sensor 1
and TP sensor 2.  Harness or connector
(TP sensor 1 and 2 circuit is open or
shorted.)
(APP sensor 2 circuit is shorted.)
 Electric throttle control actuator (TP sensor 1 and 2)
 Accelerator pedal position sensor
(APP sensor 2)
Engine operation 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: December 20092009 QX56

EC-370
< COMPONENT DIAGNOSIS >[VK56DE]
P2135 TP SENSOR
Refer to
EC-85, "Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.CHECK THROTTLE POSITION SE NSOR POWER SUPPLY CIRCUIT-I
1. Disconnect electric throttle control actuator (1) harness connec- tor.
- Illustration shows the view with intake air duct removed.
2. Turn ignition switch ON.
3. Check voltage between electric throttle control actuator (1) ter- minal 2 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 3.
3.CHECK THROTTLE POSITION SE NSOR POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric thrott le control actuator terminal 2 and ECM terminal 47.
Refer to Wiring Diagram.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit.
4.CHECK THROTTLE POSITION SENS OR POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
BBIA0354E
BBIA0371E
Voltage: Approximately 5V
PBIB2065E
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram
47 Electric throttle control actuator terminal 2 EC-432, "Wiring Diagram - ENGINE
CONTROL SYSTEM -"91 APP sensor terminal 6
Revision: December 20092009 QX56

P2135 TP SENSOREC-371
< COMPONENT DIAGNOSIS > [VK56DE]
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OK or NG
OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors.
5.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-376, "Component Inspection"
.
OK or NG
OK >> GO TO 11.
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 THROTTLE POSITI ON SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between electric thrott le control actuator terminal 4 and ECM terminal 66.
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 THROTTLE PO SITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 50 and elec tric throttle control actuator terminal 1, ECM
terminal 69 and electric throttle control actuator terminal 3.
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 THROTTLE POSITION SENSOR
Refer to EC-372, "Component Inspection"
.
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10.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
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
Continuity should exist.
Continuity should exist.
Revision: December 20092009 QX56