engine NISSAN X-TRAIL 2003 Electronic Repair Manual

DTC P0120 TP SENSOR
EC-147
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On Board Diagnosis LogicEBS00B3C
FAI L-S AFE MO DE
ECM enters in fail-safe mode when the malfunction A, B, C or D is detected.
*: The ECM enters in the fail-safe mode when the normal signal is entered to the ECM after the malfunction C was detected.
DTC Confirmation ProcedureEBS00B3D
NOTE:
lPerform “PROCEDURE FOR MALFUNCTION A, B, C AND D” first. If the 1st trip DTC cannot be con-
firmed, perform “PROCEDURE FOR MALFUNCTION E". If the 1st trip DTC cannot be confirmed,
perform “PROCEDURE FOR MALFUNCTION F".
lIf “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and
wait at least 10 seconds before conducting the next test.
74 GThrottlepositionsen-
sor 2[Ignition switch "ON"]
lGear position is "D" (A/T model)
lGear position is "1st" (M/T model)
lAccelerator pedal fully releasedLess than 4.75V
[Ignition switch “ON”]
lGear position is "D" (A/T model)
lGear position is "1st" (M/T model)
lAccelerator pedal fully depressedMore than 0.36V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0120
0120Throttle position sensor
circuitA)An excessively low or high voltage from
the throttle position sensor 1 is sent to
ECM.
lHarness or connectors
(The throttle position sensor 1 or 2 circuit
is open or shorted.)
lElectric throttle control actuator B)An excessively low or high voltage from
the throttle position sensor 2 is sent to
ECM.
C)A difference between signals from sensor
1 and sensor 2 is out of the specified
range.
D)ECM detects a voltage of power source
for sensor is excessively low or high.
lHarness or connectors
(The throttle position sensor 1, 2, accel-
erator pedal position sensor 1, 2, mass
air flow sensor, power steering pressure
sensor or refrigerant pressure sensor cir-
cuit is shorted.)
lECM
(ECM pin terminal is bend or break.)
E)Closed throttle position learning value is
excessively low.
lElectric throttle control actuator
F)Closed throttle position learning is not
performed successfully, repeatedly.
Detected items Engine operation condition in fail-safe mode
Malfunction A 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 an opening speed of approx. 5 seconds to an opening of 10 degrees.
So, the acceleration will be poor. Malfunction B
Malfunction C*
Malfunction DECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx.
5 degrees) by the return spring.

EC-148
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DTC P0120 TP SENSOR
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
PROCEDURE FOR MALFUNCTION A, B, C AND D
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 1st trip DTC is detected, go toEC-150, "
MALFUNCTIONING
A, B, C, AND D"in "Diagnostic Procedure".
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION E
With CONSULT-II
1. Turn ignition switch “ON”.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Turn ignition switch "OFF", wait at least 10 seconds.
4. Turn ignition switch "ON".
5. If 1st trip DTC is detected, go toEC-152, "
MALFUNCTION E
AND F"in "Diagnostic Procedure".
With GST
Follow the procedure “With CONSULT-II” above.
PROCEDURE FOR MALFUNCTION F
With CONSULT-II
1. Turn ignition switch "ON".
2. Select "DATA MONITOR" mode with CONSULT-II.
3. Turn ignition switch “OFF”, wait at least 10 seconds.
4. Turn ignition switch "ON".
5. Repeat steps 3 and 4, 32 times.
6. If 1st trip DTC is detected, go toEC-152, "
MALFUNCTION E
AND F"in "Diagnostic Procedure".
With GST
Follow the procedure “With CONSULT-II” above.
SEF058Y
SEF058Y
SEF058Y

EC-150
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DTC P0120 TP SENSOR
Diagnostic Procedure
EBS00B3F
MALFUNCTIONING A, B, C, AND D
1.RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
2.CHECK THROTTLE POSITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect electric throttle control actuator harness connector.
2. Turn ignition switch “ON”.
3. Check voltage between electric throttle control actuator terminal
1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
lHarness for short between ECM and electric throttle control actuator
lHarness for short between ECM and accelerator pedal position sensor
lHarness for short between ECM and mass air flow sensor
lHarness for short between ECM and power steering pressure sensor
lHarness for short between ECM and refrigerant pressure sensor
lECM pin terminal
>> Repair short to ground or short to power in harness or connectors.
PBIB0494E
PBIB0497E
Voltage: Approximately 5V
PBIB0082E

DTC P0120 TP SENSOR
EC-151
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4.CHECK THROTTLE POSITION SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Check harness continuity between electric throttle control actuator terminal 5 and engine ground.
Refer to Wiring Diagram.
3. 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 THROTTLE POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 73 and electric throttle control actuator terminal 4, ECM
terminal 74 and electric throttle control actuator terminal 2.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK THROTTLE POSITION SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Disconnect joint connector-4.
3. Check the following.
–Continuity between joint connector-4 terminal 1 and engine ground
–Joint connector-4
(Refer toPG-29, "
Harness Layout".)
Refer to Wiring Diagram.
4. Also check harness for short to power.
5. Then reconnect joint connector-4.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to power in harness or connectors.
7.CHECK THROTTLE POSITION SENSOR
Refer toEC-152, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.Continuity should exist.
Continuity should exist.
Continuity should exist.

DTC P0120 TP SENSOR
EC-153
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EC
5. Check voltage between ECM terminals 73 (TP sensor 1), 74 (TP
sensor 2) and engine ground under the following conditions.
6. If NG, replace electric throttle control actuator and go to the next
step.
7. PerformEC-31, "
Throttle Valve Closed Position Learning".
8. PerformEC-31, "
Idle Air Volume Learning".
Remove and InstallationEBS00B3H
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer toEM-17, "INTAKE MANIFOLD".
Terminal Accelerator pedal Voltage
73
(Throttle position sensor 1)Fully released More than 0.36V
Fully depressed Less than 4.75V
74
(Throttlepositionsensor2)Fully released Less than 4.75V
Fully depressed More than 0.36V
PBIB0559E

EC-154
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DTC P0121 APP SENSOR
DTC P0121 APP SENSOR
PFP:18002
Component DescriptionEBS00B3I
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 ModeEBS00B3J
Specification data are reference values.
ECM Terminals and Reference ValueEBS00B3K
Specification data are reference values and are measured between each terminal and body ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
PBIB0146E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SEN1
lIgnition switch: ON
(engine stopped)Accelerator pedal: Fully released 0.41 - 0.71V
Accelerator pedal: Fully depressed More than 3.9V
ACCEL SEN2
lIgnition switch: ON
(engine stopped)Accelerator pedal: Fully released 0.15 - 0.97V
Accelerator pedal: Fully depressed More than 3.8V
CLSD THL POS
lIgnition switch: ONAccelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
58 B Sensors' ground[Engine is running]
lWarm-up condition
lIdle speedApproximately 0V
64 OR/LAccelerator pedal
position sensor 2
power supply[Ignition switch “ON”]Approximately 2.5V
65 RSensor's power sup-
ply[Ignition switch “ON”]Approximately 5V
75 R/LAccelerator pedal
position sensor 1[Ignition switch "ON"]
lAccelerator pedal fully released0.41 - 0.71V
[Ignition switch "ON"]
lAccelerator pedal fully depressedMore than 3.9V

DTC P0121 APP SENSOR
EC-155
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EC
On Board Diagnosis LogicEBS00B3L
FAI L-S AFE MO DE
ECM enters in fail-safe mode when the malfunction is detected.
DTC Confirmation ProcedureEBS00B3M
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 10V 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 1st trip DTC is detected, go toEC-157, "
Diagnostic Procedure"
.
WITH GST
Follow the procedure “With CONSULT-II” above.
76 B/WAccelerator pedal
position sensor 2[Ignition switch "ON"]lAccelerator pedal fully released0.09 - 0.48V
[Ignition switch "ON"]
lAccelerator pedal fully depressedMore than 1.9V
86 LAccelerator pedal
position sensor 2
ground[Ignition switch “ON”]Approximately 0V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0121
0121Accelerator pedal posi-
tion sensor circuitA)An excessively low or high voltage from the
accelerator pedal position sensor 1 is sent to
ECM.
lHarness or connectors
(The accelerator pedal position
sensor 1 or 2 circuit is open or
shorted.)
lElectric throttle control actuator B)An excessively low or high voltage from the
accelerator pedal position sensor 2 is sent to
ECM.
C)A difference between signals from sensor 1 and
2 is out of the specified range.
Detected items Engine operating condition in fail-safe mode
Malfunction A 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 an opening speed of approx. 5 seconds to an opening of 10 degrees.
So, the acceleration will be poor. Malfunction B
Malfunction C
SEF058Y

DTC P0121 APP SENSOR
EC-157
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Diagnostic ProcedureEBS00B3O
1.RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
2.CHECK APP SENSOR POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness
connector.
2. Turn ignition switch “ON”.
3. Check voltage between APP sensor terminals 4, 6 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
lHarness connectors M61, F41
lHarness for open or short between ECM and accelerator pedal position sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
PBIB0494E
PBIB0498E
APP sensor terminal Voltage (V)
4Approximately2.5
6Approximately5
PBIB0560E

EC-158
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DTC P0121 APP SENSOR
4.CHECK APP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Check harness continuity between APP sensor terminal 1, 3 and engine ground.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5.DETECT MALFUNCTIONING PART
Check the following.
lHarness connectors M61, F41
lHarness for open or short between ECM and accelerator pedal position sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
6.CHECK APP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 75 and APP sensor terminal 5, ECM terminal 76 and
APP sensor terminal 2.
Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
lHarness connectors M61, F41
lHarness for open or short between ECM and accelerator pedal position sensor
>> Repair open circuit or short to ground or short to power in harness or connectors.
8.CHECK APP SENSOR
Refer toEC-159, "
Component Inspection".
OK or NG
OK >> GO TO 9.
NG >> Replace accelerator pedal assembly.
9.CHECK INTERMITTENT INCIDENT
Refer toEC-107, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT".
>>INSPECTION END Continuity should exist.
Continuity should exist.

DTC P0121 APP SENSOR
EC-159
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EC
Component InspectionEBS00B3P
ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch "ON".
3. Check voltage between ECM terminals 75 (APP sensor 1 sig-
nal), 76 (APP sensor 2 signal) and engine ground under the fol-
lowing conditions.
4. If NG, replace accelerator pedal assembly.
Remove and InstallationEBS00B3Q
ACCELERATOR PEDAL
Refer toACC-2, "ACCELERATOR CONTROL SYSTEM".
Terminal Accelerator pedal Voltage
75
(Accelerator pedal position
sensor 1)Fully released 0.41 - 0.71V
Fully depressed More than 3.9V
76
(Accelerator pedal position
sensor 2)Fully released 0.09 - 0.48V
Fully depressed More than 1.9V
PBIB0561E