NISSAN X-TRAIL 2001 Service Repair Manual

DTC P0100 MASS AIR FLOW SENSOR (MAFS)
EC-1451
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)PFP:22680
Component DescriptionEBS004Q0
The mass air flow sensor (MAFS) is placed in the stream of intake
air. It measures the intake air flow rate by measuring a part of the
entire intake air flow. It consists of a hot film that is supplied with
electric current from the ECM. The temperature of the hot film is con-
trolled by the ECM a certain amount. The heat generated by the hot
film is reduced as the intake air flows around it. The more air, the
greater the heat loss.
Therefore, the ECM must supply more electric current to maintain
the temperature of the hot film as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor ModeEBS004Q1
Specification data are reference values.
ECM Terminals and Reference ValueEBS00BR6
Specification data are reference values, and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
SEF987W
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SE
●Engine: After warming up
●Air conditioner switch: “OFF”
●Shift lever: Neutral position
●No-loadIdle 1.0 - 2.5V
2,000 rpm 2.1 - 2.7V
TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse Signal)
A8
A9R
RPower supply for ECM[Ignition switch "ON"]BATTERY VOLTAGE
(11 - 14V)
A10 R Mass air flow sensor[Engine is running]
●Warm-up condition
●Idle speed0.5 - 2.5V
[Engine is running]
●Warm-up condition
●Engine speed is 2,000 rpm1.5 - 3.5V
A24 BMass air flow sensor
ground[Engine is running]
●Warm-up condition
●Idle speedApproximately 0V
A27 W Sensor's power supply[Ignition switch "ON"]Approximately 5V
PBIB0389E
PBIB0390E

EC-1452
[YD]
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
On Board Diagnosis LogicEBS004Q3
DTC Confirmation ProcedureEBS004Q4
WITH CONSULT-II
1. Turn ignition switch “ON”, and wait at least 6 seconds.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and wait at least 3 seconds.
4. If DTC is detected, go to EC-1454, "
Diagnostic Procedure" .
D24
D26G
GECM relay (self-shutoff)[Ignition switch “ON”]
[Ignition switch “OFF”]●For a few seconds after turning ignition
switch "OFF"Approximately 0V
[Ignition switch “OFF”]
●A few seconds passed after turning ignition
switch "OFF"BATTERY VOLTAGE
(11 - 14V) TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse Signal)
DTC Malfunction is detected when ... Check Items (Possible Cause)
P0100
●An excessively high or low voltage from the sensor
is sent to ECM.●Harness or connectors
(The sensor circuit is open or shorted.)
●Mass air flow sensor
SEF817Y

DTC P0100 MASS AIR FLOW SENSOR (MAFS)
EC-1453
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Wiring DiagramEBS004Q5
TBWA0102E

EC-1454
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)
Diagnostic Procedure
EBS004Q6
1. CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect mass air flow sensor harness connector.
3. Turn ignition switch “ON”.
4. Check voltage between mass air flow sensor terminals 2, 4 and
ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING PART
Check the following.
●Harness for open or short between mass air flow sensor and ECM
●Harness for open or short between mass air flow sensor and ECM relay
>> Repair open circuit or short to ground or short to power in harness or connectors.
3. CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
3. Check harness continuity between mass air flow sensor terminal
3 and engine ground. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check harness for open or short between mass air flow sensor and ECM.
>> Repair open circuit or short to ground or short to power in harness or connectors.
SEF884Y
Terminal Voltage
2 Approximately 5V
4 Battery voltage
PBIB0360E
Continuity should exist.
PBIB0385E

DTC P0100 MASS AIR FLOW SENSOR (MAFS)
EC-1455
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5.CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor terminal 1 and ECM terminal A10. 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 MASS AIR FLOW SENSOR
Refer to EC-1455, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace mass air flow sensor.
7.CHECK INTERMITTENT INCIDENT
Refer to EC-1441, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS004Q7
MASS AIR FLOW SENSOR
1. Reconnect harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal A10 (Mass air flow sensor
signal) and ground.
4. If the voltage is out of specification, disconnect MAFS harness
connector and connect it again.
Then repeat above check.
Removal and InstallationEBS008YD
MASS AIR FLOW SENSOR
Refer to EM-120, "AIR CLEANER AND AIR DUCT" . Continuity should exist.
Condition Voltage V
Ignition switch "ON" (Engine stopped.) Approx. 1.0
Idle (Engine is warmed up to normal
operating temperature.)1.0 - 2.5
2,000 rpm (Engine is warmed up to nor-
mal operating temperature.)2.1 - 2.7
PBIB0361E

EC-1456
[YD]
DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (CIRCUIT)
DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (CIRCUIT)
PFP:22630
DescriptionEBS004Q8
The engine coolant temperature sensor is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The electrical resistance of the ther-
mistor decreases as temperature increases.

*: These data are reference values and measured between ECM terminal A11
(Engine coolant temperature sensor) and 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.
On Board Diagnosis LogicEBS004Q9
DTC Confirmation ProcedureEBS004QA
WITH CONSULT-II
1. Turn ignition switch “ON”.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Wait at least 5 seconds.
4. If DTC is detected, go to EC-1458, "
Diagnostic Procedure" .
SEF594K
Engine coolant tempera-
ture °C (°F)Voltage* (V) Resistance (kΩ)
−10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.1 - 2.9
50 (122) 2.3 0.68 - 1.00
90 (194) 1.0 0.236 - 0.260
SEF012P
DTC Malfunction is detected when ... Check Items (Possible Cause)
P0115
●An excessively high or low voltage from the sensor
is sent to ECM.●Harness or connectors
(The sensor circuit is open or shorted.)
●Engine coolant temperature sensor
SEF817Y

DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (CIRCUIT)
EC-1457
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Wiring DiagramEBS004QB
TBWA0103E

EC-1458
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DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (CIRCUIT)
Diagnostic Procedure
EBS004QC
1. CHECK ECTS POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect engine coolant temperature sensor harness connec-
tor.
3. Turn ignition switch “ON”.
4. Check voltage between ECTS terminal 1 and ground with CON-
SULT-II or tester.
OK or NG
OK >> GO TO 2.
NG >> Repair harness or connectors.
2. CHECK ECTS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch “OFF”.
2. Check harness continuity between ECTS terminal 2 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 3.
NG >> Repair harness or connectors.
3. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-1459, "
Component Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Replace engine coolant temperature sensor.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-1441, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
PBIB0374E
Voltage: Approximately 5V
PBIB0080E
Continuity should exist.

DTC P0115 ENGINE COOLANT TEMPERATURE (ECT) SENSOR (CIRCUIT)
EC-1459
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Component InspectionEBS004QD
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

*: These data are measured between ECM terminal A11 (Engine coolant tem-
perature sensor) and body ground.
2. If NG, replace engine coolant temperature sensor.
Removal and InstallationEBS008YF
ENGINE COOLANT TEMPERATURE SENSOR
Refer to EM-182, "CYLINDER HEAD" .
PBIB0081E
Engine coolant temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P

EC-1460
[YD]
DTC P0120 ACCELERATOR PEDAL POSITION SENSOR
DTC P0120 ACCELERATOR PEDAL POSITION SENSOR
PFP:18002
DescriptionEBS004R5
The accelerator work unit is installed on the upper end of the accelerator pedal assembly. The accelerator
pedal position sensor 1, 2 and accelerator pedal released position switch are built into the accelerator work
unit. The sensors detect the accelerator pedal position and sends a signal to the ECM. The ECM uses the sig-
nal to determine the amount of fuel to be injected.
The accelerator pedal released position switch detects accelerator pedal released position and sends the sig-
nal to the ECM. The ECM will then determine engine idle conditions. The signal is also used for diagnosing the
accelerator pedal position sensor.
CONSULT-II Reference Value in Data Monitor ModeEBS004R6
Specification data are reference values.
*: Accelerator pedal position sensor 2 signal is converted by ECM internally. Thus, it differ from ECM terminals voltage.
ECM Terminals and Reference ValueEBS004R7
Specification data are reference values and are measured between each terminal and 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.
PBIB0463E
MONITOR ITEM CONDITION SPECIFICATION
ACCEL POS SEN
●Ignition switch: ON
(Engine stopped)Accelerator pedal: fully released 0.8 - 1.3V
Accelerator pedal: fully depressed More than 3.5V
ACCEL SEN 2*
●Ignition switch: ON
(Engine stopped)Accelerator pedal: fully released 0.3 - 1.8V
Accelerator pedal: fully depressed More than 3.0V
OFF ACCEL SW
●Ignition switch: ON
(Engine stopped)Accelerator pedal: fully released ON
Accelerator pedal: slightly
depressed OFF
TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse Signal)
A21 BAccelerator pedal
released position switch
ground[Ignition switch “ON”]Approximately 0V
A22 LGAccelerator pedal position
sensor 1 ground[Ignition switch “ON”]Approximately 0V