2005 NISSAN X-TRAIL check

DTC P0037, P0038 HO2S2 HEATER
EC-149
[QR (WITH EURO-OBD)]
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2. CHECK HO2S2 POWER SUPPLY CIRCUIT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Turn ignition switch ON.
3. Check voltage between HO2S2 terminal 4 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.

Harness connectors E60, F36

Fuse block (J/B) connector E103

10A fuse

Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair open circuit or short to ground or short or power in harness or connectors.
4. CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 2 and HO2S2 terminal 1.
Refer to Wiring Diagram.
4. 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 HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-150, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace heated oxygen sensor 2.
PBIB0500E
Voltage: Battery voltage
PBIB0541E
Continuity should exist.

EC-150
[QR (WITH EURO-OBD)]
DTC P0037, P0038 HO2S2 HEATER

6. CHECK INTERMITTENT INCIDENT
Refer to EC-124, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS010MZ
HEATED OXYGEN SENSOR 2 HEATER
1. Check resistance between HO2S2 terminals as follows.
2. If NG, replace heated oxygen sensor 2.
CAUTION:

Discard any heated oxygen sensor which has been dropped
from a height of more than 0.5 m (19.7 in) onto a hard sur-
face such as a concrete floor; use a new one.

Before installing new oxygen sensor, clean exhaust system
threads using Oxygen Sensor Thread Cleaner tool and
approved anti-seize lubricant.
Removal and InstallationEBS010N0
HEATED OXYGEN SENSOR 2
Refer to EX-2, "EXHAUST SYSTEM" .
Terminal No. Resistance
1 and 4 5.0 - 7.0 Ω [at 25°C (77°F)]
2 and 1, 3, 4
∞ Ω
(Continuity should not exist)
3 and 1, 2, 4
PBIB0542E

EC-154
[QR (WITH EURO-OBD)]
DTC P0102, P0103 MAF SENSOR

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.
Diagnostic ProcedureEBS010N6
1. INSPECTION START
Which malfunction (P0102 or P0103) is duplicated?
P0102 or P0103
P0102 >> GO TO 2.
P0103 >> GO TO 3.
2. CHECK INTAKE SYSTEM
Check the following for connection.

Air duct

Va c u u m h o s e s

Intake air passage between air duct and intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
50 OR Mass air flow sensor[Ignition switch: ON]Approximately 0.4V
[Engine is running]

Warm-up condition

Idle speed0.7 - 1.1V (QR20DE)
0.8 - 1.2V (QR25DE)
[Engine is running]

Warm-up condition

Engine is revving from idle to about 4,000 rpm0.7 - 1.1 to Approximately 4.0V
(QR20DE)
0.8 - 1.2 to Approximately 4.0V
(QR25DE)
(Check for liner voltage rise in
response to engine being
increased to about 4,000 rpm.)
67 B/PSensor ground
(Mass air flow sensor)[Engine is running]

Warm-up condition

Idle speedApproximately 0V

DTC P0102, P0103 MAF SENSOR
EC-155
[QR (WITH EURO-OBD)]
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3. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-132, "
Ground Inspection" .
OK or NG
OK >> GO TO 4.
NG >> Repair or replace ground connections.
PBIB2021E

EC-156
[QR (WITH EURO-OBD)]
DTC P0102, P0103 MAF SENSOR

4. CHECK MAF SENSOR POWER SUPPLY CIRCUIT
1. Disconnect MAF sensor harness connector.
2. Turn ignition switch ON.
3. Check voltage between MAF sensor terminals 2 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors F41, M61

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.
6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
PBIB0495E
Voltage: Battery voltage
PBIB1168E
Continuity should exist.

DTC P0102, P0103 MAF SENSOR
EC-157
[QR (WITH EURO-OBD)]
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7. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 50.
Refer to Wiring Diagram.
2. 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 MASS AIR FLOW SENSOR
Refer to EC-157, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace mass air flow sensor.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-124, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS01FF1
MASS AIR FLOW SENSOR
With CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-II and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1” and check indication under the follow-
ing conditions.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
5. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 4 again.
If OK, go to next step.
6. Turn ignition switch OFF.
7. Disconnect mass air flow sensor harness connector and reconnect it again.
8. Perform step 2 to 4 again.
9. If NG, clean or replace mass air flow sensor.Continuity should exist.
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating
temperature.)0.7 - 1.1V (QR20DE)
0.8 - 1.2V (QR25DE)
Idle to about 4,000 rpm0.7 - 1.1 to 2.4 (QR20DE)*
0.8 - 1.2 to 2.4 (QR25DE)*
SEF178Y

EC-158
[QR (WITH EURO-OBD)]
DTC P0102, P0103 MAF SENSOR

Without CONSULT-II
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 50 (Mass air flow sensor
signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
a. Check for the cause of uneven air flow through mass air flow sensor. Refer to following.

Crushed air ducts

Malfunctioning seal of air cleaner element

Uneven dirt of air cleaner element

Improper specification of intake air system parts
b. If NG, repair or replace malfunctioning part and perform step 2 to 3 again.
If OK, go to next step.
5. Turn ignition switch OFF.
6. Disconnect mass air flow sensor harness connector and reconnect it again.
7. Perform step 2 and 3 again.
8. If NG, clean or replace mass air flow sensor.
Removal and InstallationEBS010N8
MASS AIR FLOW SENSOR
Refer to EM-16, "AIR CLEANER AND AIR DUCT" .
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating
temperature.)0.7 - 1.1V (QR20DE)
0.8 - 1.2V (QR25DE)
Idle to about 4,000 rpm0.7 - 1.1 to 2.4 (QR20DE)*
0.8 - 1.2 to 2.4 (QR25DE)*
MBIB0017E

EC-162
[QR (WITH EURO-OBD)]
DTC P0112, P0113 IAT SENSOR

Diagnostic ProcedureEBS010ND
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-132, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
PBIB2021E