2009 NISSAN LATIO service

DTC P2122, P2123 APP SENSOR
EC-943
< SERVICE INFOMATION >
[MR TYPE 1] C
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If DTC Confirmation Procedure has been previously conduc
ted, 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.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-944, " Diagnosis Procedure " .
Wiring Diagram INFOID:0000000004537477 BBWA2652E

EC-944< SERVICE INFOMATION >
[MR TYPE 1]
DTC P2122, P2123 APP SENSOR
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
Diagnosis Procedure INFOID:00000000045374781.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screw on the body.
Refer to EC-632, " Ground Inspection " .
OK or NG OK >> GO TO 2.TER-
MI-
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NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
102 SB Sensor power supply
(APP sensor 2) [Ignition switch: ON]
Approximately 5V
103 GR Accelerator pedal position
sensor 2 [Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released 0.3 - 0.6V
[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed 1.95 - 2.4V
104 Y Sensor ground
(APP sensor 2) [Engine is running]
• Warm-up condition
• Idle speed Approximately 0V
106 P Sensor power supply
(APP sensor 1) [Ignition switch: ON]
Approximately 5V
110 G Accelerator pedal position
sensor 1 [Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released 0.6 - 0.9V
[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed 3.9 - 4.7V
111 R Sensor ground
(APP sensor 1) [Engine is running]
• Warm-up condition
• Idle speed Approximately 0V:
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15 BBIA0698E

DTC P2122, P2123 APP SENSOR
EC-945
< SERVICE INFOMATION >
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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-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 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 111 and APP sensor terminal 2. 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. 4.
CHECK APP SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 110 and APP sensor terminal 3. 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-946, " Component Inspection " .
OK or NG OK >> GO TO 7.
NG >> GO TO 6. 6.
REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly. BBIA0705E
Voltage: Approximately 5V
PBIA9606J
Continuity should exist.
Continuity should exist.

EC-946< SERVICE INFOMATION >
[MR TYPE 1]
DTC P2122, P2123 APP SENSOR
2. Perform EC-572, " Accelerator Pedal Released Position Learning " .
3. Perform EC-572, " Throttle Valve Closed Position Learning " .
4. Perform EC-572, " Idle Air Volume Learning " .
>> INSPECTION END 7.
CHECK INTERMITTENT INCIDENT
Refer to EC-626 .
>> INSPECTION END
Component Inspection INFOID:0000000004537479
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-572, " Accelerator Pedal Released Position Learning " .
6. Perform EC-572, " Throttle Valve Closed Position Learning " .
7. Perform EC-572, " Idle Air Volume Learning " .
Removal and Installation INFOID:0000000004537480
ACCELERATOR PEDAL
Refer to ACC-3 .
Terminal Accelerator pedal Voltage
110
(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

DTC P2127, P2128 APP SENSOR
EC-947
< SERVICE INFOMATION >
[MR TYPE 1] C
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DTC P2127, P2128 APP SENSOR
Component Description INFOID:0000000004537481
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 positi on sensor. The ECM uses this signal for the engine oper-
ation such as fuel cut.
CONSULT-III Reference Val ue in Data Monitor Mode INFOID:0000000004537482
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 Logic INFOID:0000000004537483
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. 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
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.)
[Crankshaft position sensor (POS) circuit
is shorted.]
(EVAP control system pressure sensor
circuit is shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
• EVAP control system pressure sensor
• Accelerator pedal position sensor (APP sensor 2)
• Crankshaft position sensor (POS)
• Refrigerant pressure 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.

DTC P2127, P2128 APP SENSOR
EC-949
< SERVICE INFOMATION >
[MR TYPE 1] C
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Wiring Diagram
INFOID:0000000004537485
Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals wh en measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground. BBWA3074E

EC-950< SERVICE INFOMATION >
[MR TYPE 1]
DTC P2127, P2128 APP SENSOR
Diagnosis Procedure INFOID:00000000045374861.
CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to EC-632, " Ground Inspection " .
TER-
MI-
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NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
74 W Sensor power supply
(Refrigerant pressure sen-
sor) [Ignition switch: ON]
Approximately 5V
75 BR Sensor power supply
[Crankshaft position sensor
(POS)] [Ignition switch: ON]
Approximately 5V
76 W EVAP control system pres-
sure sensor power supply [Ignition switch: ON]
Approximately 5V
102 SB Sensor power supply
(APP sensor 2) [Ignition switch: ON]
Approximately 5V
103 GR Accelerator pedal position
sensor 2 [Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released 0.3 - 0.6V
[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed 1.95 - 2.4V
104 Y Sensor ground
(APP sensor 2) [Engine is running]
• Warm-up condition
• Idle speed Approximately 0V
106 P Sensor power supply
(APP sensor 1) [Ignition switch: ON]
Approximately 5V
110 G Accelerator pedal position
sensor 1 [Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully released 0.6 - 0.9V
[Ignition switch: ON]
• Engine stopped
• Accelerator pedal: Fully depressed 3.9 - 4.7V
111 R Sensor ground
(APP sensor 1) [Engine is running]
• Warm-up condition
• Idle speed Approximately 0V:
Vehicle front
1. Body ground E24 2. Engine ground F9 3. Engine ground F16
4. Body ground E15 BBIA0698E

DTC P2127, P2128 APP SENSOR
EC-951
< SERVICE INFOMATION >
[MR TYPE 1] C
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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 (1) harness connector.
2. Turn ignition switch ON.
3. Check voltage between APP sensor terminal 5 and ground with CONSULT-III or tester.
OK or NG OK >> GO TO 6.
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 5 and ECM terminal 102.
Refer to Wiring Diagram.
OK or NG OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. 4.
CHECK COMPONENTS POWER SUPPLY CIRCUIT
Check harness for short to power and short to ground, between the following terminals.
OK or NG OK >> GO TO 5.
NG >> Repair short to ground or short to power in harness or connectors. 5.
CHECK COMPONENTS
Check the following.
• Crankshaft position sensor (POS) (Refer to EC-780, " Component Inspection " .)
• EVAP control system pressure sensor (Refer to EC-831, " Component Inspection " .) BBIA0705E
Voltage: Approximately 5V
PBIA9607J
Continuity should exist.
ECM terminal Sensor terminal Reference Wiring Diagram 74 Refrigerant pressure sensor terminal 3 EC-1006, " Wiring Diagram "
75 Crankshaft position sensor (POS) terminal 1
EC-776, " Wiring Diagram "
76 EVAP control system pressure sensor terminal 3
EC-834, " Wiring Diagram "
102 APP sensor terminal 5
EC-949, " Wiring Diagram "