2008 NISSAN LATIO ignition

DTC P2138 APP SENSOR
EC-493
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
DTC P2138 APP SENSOR
Component DescriptionINFOID:0000000001703033
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:0000000001703034
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differs from ECM terminal voltage.
On Board Diagnosis LogicINFOID:0000000001703035
This self-diagnosis has the one trip detection logic.
NOTE:
If DTC P2138 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643.
Refer to EC-400
.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
PBIB1741E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN 1• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.6 - 0.9V
Accelerator pedal: Fully depressed 4.0 - 4.8V
ACCEL SEN 2*• Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.6 - 0.9V
Accelerator pedal: Fully depressed 3.9 - 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
P2138
2138Accelerator pedal posi-
tion sensor circuit range/
performanceRationally 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.)
[Crankshaft position sensor (POS) circuit
is shorted.]
(EVAP control system pressure sensor
circuit is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
• Accelerator pedal position sensor
(APP sensor 1 and 2)
• Crankshaft position sensor (POS)
• EVAP control system pressure sensor
• Refrigerant pressure sensor

EC-494
< SERVICE INFORMATION >
DTC P2138 APP SENSOR
DTC Confirmation Procedure
INFOID:0000000001703036
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-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-496, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
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.
SEF058Y

EC-496
< SERVICE INFORMATION >
DTC P2138 APP SENSOR
Diagnosis Procedure
INFOID:0000000001703038
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body.
Refer to EC-142, "
Ground Inspection".
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
74 WSensor power supply
(Refrigerant pressure sen-
sor)[Ignition switch: ON]Approximately 5V
75 BRSensor power supply
[Crankshaft position sensor
(POS)][Ignition switch: ON]Approximately 5V
76 WEVAP control system pres-
sure sensor power supply[Ignition switch: ON]Approximately 5V
102 SBSensor power supply
(APP sensor 2)[Ignition switch: ON]Approximately 5V
103 GRAccelerator pedal position
sensor 2[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released0.3 - 0.6V
[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed1.95 - 2.4V
104 YSensor ground
(APP sensor 2)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
106 PSensor power supply
(APP sensor 1)[Ignition switch: ON]Approximately 5V
11 0 GAccelerator pedal position
sensor 1[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released0.6 - 0.9V
[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed3.9 - 4.7V
111 RSensor ground
(APP sensor 1)[Engine is running]
•Warm-up condition
• Idle speedApproximately 0V
:Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15
BBIA0698E

DTC P2138 APP SENSOR
EC-497
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
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 (1) harness
connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 4 and ground with
CONSULT-II 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 5 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 7.
NG >> GO TO 4.
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 5 and ECM terminal 102.
Refer to Wiring Diagram.
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 2 POWER SUPPLY CIRCUIT-III
Check harness for short to power and short to ground, between the following terminals.
BBIA0705E
Voltage: Approximately 5V
PBIA9606J
Voltage: Approximately 5V
PBIA9607J
Continuity should exist.

EC-498
< SERVICE INFORMATION >
DTC P2138 APP SENSOR
OK or NG
OK >> GO TO 6.
NG >> Repair short to ground or short to power in harness or connectors.
6.CHECK COMPONENTS
Check the following.
• Crankshaft position sensor (POS) (Refer to EC-301, "
Component Inspection".)
• EVAP control system pressure sensor (Refer to EC-353, "
Component Inspection".)
• Refrigerant pressure sensor (Refer to MTC-22
.)
OK or NG
OK >> GO TO 11.
NG >> Replace malfunctioning component.
7.CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following;
ECM terminal 111 and APP sensor terminal 2,
ECM terminal 104 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 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between the following;
ECM terminal 110 and APP sensor terminal 3,
ECM terminal 103 and APP sensor terminal 6.
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-499, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> GO TO 10.
10.REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Perform EC-76, "
Accelerator Pedal Released Position Learning".
3. Perform EC-76, "
Throttle Valve Closed Position Learning".
4. Perform EC-76, "
Idle Air Volume Learning".
ECM terminal Sensor terminalReference Wiring Diagram
74 Refrigerant pressure sensor terminal 3EC-542, "
Wiring Diagram"
75 Crankshaft position sensor (POS) terminal 1EC-297, "Wiring Diagram"
76 EVAP control system pressure sensor terminal 3EC-357, "Wiring Diagram"
102 APP sensor terminal 5EC-495, "Wiring Diagram"
Continuity should exist.
Continuity should exist.

DTC P2138 APP SENSOR
EC-499
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
>>INSPECTION END
11 .CHECK INTERMITTENT INCIDENT
Refer to EC-136
.
>>INSPECTION END
Component InspectionINFOID:0000000001703039
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ON.
3. Check voltage between ECM terminals 110 (APP sensor 1 sig-
nal), 103 (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-76, "
Accelerator Pedal Released Position Learning".
6. Perform EC-76, "
Throttle Valve Closed Position Learning".
7. Perform EC-76, "
Idle Air Volume Learning".
Removal and InstallationINFOID:0000000001703040
ACCELERATOR PEDAL
Refer to ACC-3.
Terminal Accelerator pedal Voltage
11 0
(Accelerator pedal position
sensor 1)Fully released 0.6 - 0.9V
Fully depressed 3.9 - 4.7V
103
(Accelerator pedal position
sensor 2)Fully released 0.3 - 0.6V
Fully depressed 1.95 - 2.4V
PBIA9572J

EC-500
< SERVICE INFORMATION >
DTC P2A00 A/F SENSOR 1
DTC P2A00 A/F SENSOR 1
Component DescriptionINFOID:0000000001703041
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 measurement = 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).
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000001703042
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001703043
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:0000000001703044
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 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
PBIB3353E
PBIB3354E
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1) • Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 2.2V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P2A00
2A00Air 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.• Air fuel ratio (A/F) sensor 1
• Air fuel ratio (A/F) sensor 1 heater
• Fuel pressure
• Fuel injector
• Intake air leaks

DTC P2A00 A/F SENSOR 1
EC-501
< SERVICE INFORMATION >
C
D
E
F
G
H
I
J
K
L
MA
EC
N
P O
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-II.
4. Clear the self-learning coefficient by touching “CLEAR”.
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 min-
utes.
9. If 1st trip DTC is detected, go to EC-503, "
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 (1) harness
connector.
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-503, "
Diagnosis Procedure".
PBIB2035E
BBIA0701E