ignition INFINITI QX56 2008 Factory Service Manual

EC-374
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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
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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-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

EC-376
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P2127, P2128 APP SENSOR
>>
INSPECTION END
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001365838
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: March 2010 2008 QX56

P2135 TP SENSOREC-377
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P2135 TP SENSOR
Component DescriptionINFOID:0000000001365840
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 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:0000000001365842
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, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001365843
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-377, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-lII” above.
Diagnosis ProcedureINFOID:0000000001365845
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
PBIB0145E
DTC No. Trouble diagnosis name DTC detecting conditionPossible 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: March 2010 2008 QX56

EC-378
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P2135 TP SENSOR
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 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 SENSOR 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.
Revision: March 2010 2008 QX56

P2135 TP SENSOREC-379
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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-384, "
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 POSITION 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 POSITION 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-380, "
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".
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

EC-380
< COMPONENT DIAGNOSIS >[VK56DE]
P2135 TP SENSOR
>>
INSPECTION END
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001365846
THROTTLE POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform EC-18, "
Throttle Valve Closed Position Learning".
3. Turn ignition switch ON.
4. Set selector lever to D position.
5. Check voltage between ECM terminals 50 (TP sensor 1 signal), 69 (TP sensor 2 signal) and ground under the following condi-
tions.
6. If NG, replace electric throttle control actuator and go to the next step.
7. Perform EC-18, "
Throttle Valve Closed Position Learning".
8. Perform EC-18, "
Idle Air Volume Learning".
Terminal Accelerator pedal Voltage
50
(Throttle position sensor 1) Fully released
More than 0.36V
Fully depressed Less than 4.75V
69
(Throttle position sensor 2) Fully released
Less than 4.75V
Fully depressed More than 0.36V
PBIB1530E
Revision: March 2010 2008 QX56

P2138 APP SENSOREC-381
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P2138 APP SENSOR
Component DescriptionINFOID:0000000001528877
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:0000000001528879
This self-diagnosis has the on e trip detection logic.
NOTE:
If DTC P2138 is displayed with DTC P0643, first pe rform the trouble 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 ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001528880
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-III
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-382, "
Diagnosis Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III” above.
PBIB1741E
DTC No. Trouble diagnosis nameDTC detecting condition Possible cause
P2138
2138 Accelerator pedal position
sensor circuit range/per-
formance Rationally incorrect voltage is sent to ECM
compared with the signals from APP sensor 1
and APP sensor 2. • Harness or connector
(APP sensor 1 and 2 circuit is open or
shorted.)
(TP sensor circuit is shorted.)
• Accelerator pedal position sensor 1 and 2
• Electric throttle control actuator
(TP sensor)
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-382
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P2138 APP SENSOR
Diagnosis Procedure
INFOID:0000000001528882
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-III 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 2 POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ON.
2. Check voltage between APP sensor terminal 6 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 4.
BBIA0354E
BBIA0361E
Voltage: Approximately 5V
JMBIA0601ZZ
Voltage: Approximately 5V
JMBIA0602ZZ
Revision: March 2010 2008 QX56

P2138 APP SENSOREC-383
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4.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 5.
NG >> Repair open circuit in harness or connectors.
5.CHECK APP SENSOR 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals
OK or NG
OK >> GO TO 6.
NG >> Repair short to ground or short to power in harness connectors.
6.CHECK THROTTLE POSITION SENSOR
Refer to EC-380, "
Component Inspection" .
OK or NG
OK >> GO TO 12.
NG >> GO TO 7.
7.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
8.CHECK APP SENSOR 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, 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 9.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
9.CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 106 and APP sensor terminal 2, ECM terminal 98 and APP sensor terminal 5.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power. Continuity should exist.
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