2009 INFINITI QX56 sensor

P2138 APP SENSOREC-375
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
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-372, "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 CI RCUIT 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-432, "Wiring Diagram - ENGINE
CONTROL SYSTEM -"91 APP sensor terminal 6
Continuity should exist.
Continuity should exist.
Revision: December 20092009 QX56

EC-376
< COMPONENT DIAGNOSIS >[VK56DE]
P2138 APP SENSOR
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
10.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-376, "Component Inspection"
.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11.
11 .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
12.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000003771698
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

P2A00, P2A03 A/F SENSOR 1EC-377
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P2A00, P2A03 A/F SENSOR 1
Component DescriptionINFOID:0000000003771699
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is composed an elec-
trode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise m
easurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800 °C
(1,472 °F).
On Board Diagnosis LogicINFOID:0000000003771700
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to LEAN side or RICH side.
DTC Confirmation ProcedureINFOID:0000000003771701
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 11V at idle.
WITH CONSULT-IIl
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-IIl.
4. Clear the self-learning coefficient by touching “CLEAR”.
PBIB3353E
PBIB3354E
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P2A00
2A00
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit range/performance  The output voltage computed by ECM from the
A/F sensor 1 signal is shifted to the lean side for
a specified period.
 The A/F signal computed by ECM from the A/F
sensor 1 signal is shifted to the rich side for a
specified period.  A/F sensor 1
 A/F sensor 1 heater
 Fuel pressure
 Fuel injector
 Intake air leaks
P2A03
2A03
(Bank 2)
Revision: December 20092009 QX56

EC-378
< COMPONENT DIAGNOSIS >[VK56DE]
P2A00, P2A03 A/F SENSOR 1
5. Turn ignition switch OFF and wait at least 10 seconds.
6. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
7. Let engine idle for 1 minute.
8. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.
9. Check 1st trip DTC.
10. If 1st trip DTC is detected, go to
EC-378, "Diagnosis Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector.
4. Start engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Select Service $03 with GST and make sure that DTC P0102 is detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine and keep the engine speed between 3,500 and 4,000 rpm for 1 minute under no load.
9. Let engine idle for 1 minute.
10. Keep engine speed between 2,500 and 3,000 rpm for 20 min- utes.
11. Select Service $07 with GST. If 1st trip DTC is detected, go to EC-378, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771702
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.RETIGHTEN A/F SENSOR 1
BBIA0368E
BBIA0354E
Revision: December 20092009 QX56

P2A00, P2A03 A/F SENSOR 1EC-379
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
1. Loosen and retighten the A/F sensor 1.
>> GO TO 3.
3.CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle.
2. Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4.CLEAR THE SELF-LEARNING DATA
With CONSULT-IIl
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “W ORK SUPPORT” mode with CONSULT-IIl.
3. Clear the self-learning control coefficient by touching “CLEAR”.
4. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-IIl
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-456, "DTC Index"
.
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-169
or EC-174.
No >> GO TO 5.
5.CHECK HARNESS CONNECTOR
1. Turn ignition switch OFF. Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E
BBIA0368E
Revision: December 20092009 QX56

EC-380
< COMPONENT DIAGNOSIS >[VK56DE]
P2A00, P2A03 A/F SENSOR 1
2. Disconnect A/F sensor 1 harness connector.
3. Check harness connector for water.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace harness connector.
6.CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT
1. Turn ignition switch ON.
2. Check voltage between A/F sensor 1 terminal 4 and ground with CONSULT-IIl or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors E5, F14
 IPDM E/R harness connector E119
 15A fuse
 Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
8.CHECK A/F SENSOR 1 INPUT SIGN AL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between A/F sensor 1 terminal and ECM terminal as follows.
Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.Water should not exit.
BBIA0376E
Voltage: Battery voltage
PBIB3308E
A/F sensor 1 terminal ECM terminal
Bank1 135
256
Bank 2 116
275
Continuity should exist.
Revision: December 20092009 QX56

P2A00, P2A03 A/F SENSOR 1EC-381
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
5. Also check harness for 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 A/F SENSOR 1 HEATER
Refer to EC-96, "Component Inspection"
.
OK or NG
OK >> GO TO 10.
NG >> GO TO 11.
10.CHECK INTERMITTENT INCIDENT
Perform GI-35, "How to Check Terminal"
and GI-38, "Intermittent Incident".
OK or NG
OK >> GO TO 11.
NG >> Repair or replace.
11 .REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air f uel ratio (A/F) sensor 1.
CAUTION:
 Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
 Before installing new A/F senso r, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>> GO TO 12.
12.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select “A/F ADJ-B1” and “” in “DATA MONITOR” mode with CONSULT-lll.
3. Make sure that “0.000” is displayed on CONSULT-lll screen.
OK or NG
OK >> INSPECTION END
NG >> GO TO 13.
13.CLEAR THE SELF-LEARNING DATA
With CONSULT-lll
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-lll.
3. Clear the self-learning control coefficient by touching “CLEAR”.
Without CONSULT-lll
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 135116
256275
Continuity should not exist.
Revision: December 20092009 QX56

EC-382
< COMPONENT DIAGNOSIS >[VK56DE]
P2A00, P2A03 A/F SENSOR 1
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con-
nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-55, "Malfunction Indicator
Lamp (MIL)".
8. Make sure DTC P0000 is displayed.
>> GO TO 14.
14.CONFIRM A/F ADJUSTMENT DATA
1. Turn ignition switch OFF and then ON.
2. Select “A/F ADJ-B1” and “A/F ADJ-B2” in “DATA MONITOR” mode with CONSULT-IIl.
3. Make sure that “0.000” is displayed on CONSULT-IIl screen.
>>INSPECTION END
BBIA0368E
Revision: December 20092009 QX56