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POWER SUPPLY CIRCUIT FOR ECM
EC-703
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5.CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch “ON” and then “OFF”.
3. Check voltage between ECM terminals A8, A9 and ground with
CONSULT-II or tester.
OK or NG
OK >> Check EDU power supply circuit. Refer toEC-758,
"Diagnostic Procedure".
NG >> GO TO 6.
6.CHECK ECM POWER SUPPLY CIRCUIT-III
1. Disconnect ECM relay.
2. Check voltage between relay terminals 1, 6 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 8.
NG >> GO TO 7.
7.DETECT MALFUNCTIONING PART
Check the following.
lHarness connectors E65, F6
l20A fuse
lHarness for open or short between ECM relay and battery
>> Repair open circuit or short to ground or short to power in harness or connectors. Vo l ta g e :
After turning ignition switch "OFF", battery
voltage will exist for a few seconds, then
drop to approximately 0V.
PBIB0357E
PBIB0377E
Voltage: Battery voltage
PBIB0359E
Page 1818 of 3066
![NISSAN X-TRAIL 2003 Electronic Repair Manual EC-704
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POWER SUPPLY CIRCUIT FOR ECM
8.CHECK OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals D24, D26 and ECM relay NISSAN X-TRAIL 2003 Electronic Repair Manual EC-704
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POWER SUPPLY CIRCUIT FOR ECM
8.CHECK OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals D24, D26 and ECM relay](/manual-img/5/57402/w960_57402-1817.png)
EC-704
[YD]
POWER SUPPLY CIRCUIT FOR ECM
8.CHECK OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals D24, D26 and ECM relay terminal 2. Refer to Wiring
Diagram.
3. 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 ECM POWER SUPPLY CIRCUIT-IV
1. Check harness continuity between ECM terminals A8, A9 and ECM relay terminal 7. Refer to Wiring Dia-
gram.
2. Also check harness for short to ground and short to power.
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 ECM RELAY
Refer toEC-705, "
Component Inspection".
OK or NG
OK >> GO TO 11.
NG >> Replace ECM relay.
11 .CHECK ECM POWER SUPPLY CIRCUIT-V
1. Turn ignition switch “OFF”.
2. Check voltage between ECM terminal A31 and ground.
OK or NG
OK >> GO TO 13.
NG >> GO TO 12.
12.DETECT MALFUNCTIONING PART
Check the following.
lHarness connectors E65, F6
l20A fuse
lHarness for open or short between ECM and fuse
>> Repair open circuit or short to ground or short to power in harness or connectors. Continuity should exist.
Continuity should exist.
Voltage: Battery voltage
PBIB0478E
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POWER SUPPLY CIRCUIT FOR ECM
EC-705
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13.CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminals A5, A6, A7 and engine ground. Refer to Wiring Dia-
gram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 14.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
14.CHECK INTERMITTENT INCIDENT
Refer toEC-699, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT".
>>INSPECTION END
Component InspectionEBS003PG
ECM RELAY
1. Apply 12V direct current between ECM relay terminals 1 and 2.
2. Check continuity between relay terminals 3 and 5, 6 and 7.
3. If NG, replace ECM relay.Continuity should exist.
Condition Continuity
12V direct current supply between ter-
minals 1 and 2Ye s
OFF No
PBIB0077E
Page 1820 of 3066
![NISSAN X-TRAIL 2003 Electronic Repair Manual EC-706
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)
DTCP0100MASSAIRFLOWSENSOR(MAFS)
PFP:22680
Component DescriptionEBS004Q0
The mass air flow sensor (MAFS) is placed in the stream of intake
air. It meas NISSAN X-TRAIL 2003 Electronic Repair Manual EC-706
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)
DTCP0100MASSAIRFLOWSENSOR(MAFS)
PFP:22680
Component DescriptionEBS004Q0
The mass air flow sensor (MAFS) is placed in the stream of intake
air. It meas](/manual-img/5/57402/w960_57402-1819.png)
EC-706
[YD]
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
DTCP0100MASSAIRFLOWSENSOR(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.
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
lEngine: After warming up
lAir conditioner switch: “OFF”
lShift lever: Neutral position
lNo-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]
lWarm-up condition
lIdle speed0.5 - 2.5V
[Engine is running]
lWarm-up condition
lEngine speed is 2,000 rpm1.5 - 3.5V
A24 BMass air flow sensor
ground[Engine is running]
lWarm-up condition
lIdle speedApproximately 0V
A27 W Sensor's power supply[Ignition switch "ON"]Approximately 5V
PBIB0389E
PBIB0390E
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EC-707
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
On Board Diagnosis LogicEBS004Q3
DTC Co NISSAN X-TRAIL 2003 Electronic Repair Manual DTCP0100MASSAIRFLOWSENSOR(MAFS)
EC-707
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
On Board Diagnosis LogicEBS004Q3
DTC Co](/manual-img/5/57402/w960_57402-1820.png)
DTCP0100MASSAIRFLOWSENSOR(MAFS)
EC-707
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: 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 toEC-709, "
Diagnostic Procedure".
D24
D26G
GECM relay (self-shutoff)[Ignition switch “ON”]
[Ignition switch “OFF”]lFor a few seconds after turning ignition
switch "OFF"Approximately 0V
[Ignition switch “OFF”]
lA 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
lAn excessively high or low voltage from the sensor
is sent to ECM.lHarness or connectors
(The sensor circuit is open or shorted.)
lMass air flow sensor
SEF817Y
Page 1822 of 3066
EC-708
[YD]
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
Wiring Diagram
EBS004Q5
TBWA0102E
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EC-709
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Diagnostic ProcedureEBS004Q6
1.CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect mass air flow sens NISSAN X-TRAIL 2003 Electronic Repair Manual DTCP0100MASSAIRFLOWSENSOR(MAFS)
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Diagnostic ProcedureEBS004Q6
1.CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch “OFF”.
2. Disconnect mass air flow sens](/manual-img/5/57402/w960_57402-1822.png)
DTCP0100MASSAIRFLOWSENSOR(MAFS)
EC-709
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Diagnostic ProcedureEBS004Q6
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.
lHarness for open or short between mass air flow sensor and ECM
lHarness 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
2Approximately5V
4 Battery voltage
PBIB0360E
Continuity should exist.
PBIB0385E
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![NISSAN X-TRAIL 2003 Electronic Repair Manual EC-710
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)
5.CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor ter NISSAN X-TRAIL 2003 Electronic Repair Manual EC-710
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DTC P0100 MASS AIR FLOW SENSOR (MAFS)
5.CHECK MAFS INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between mass air flow sensor ter](/manual-img/5/57402/w960_57402-1823.png)
EC-710
[YD]
DTC P0100 MASS AIR FLOW SENSOR (MAFS)
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 toEC-710, "
Component Inspection".
OK or NG
OK >> GO TO 7.
NG >> Replace mass air flow sensor.
7.CHECK INTERMITTENT INCIDENT
Refer toEC-699, "
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 toEM-112, "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