2002 NISSAN TERRANO Service Repair Manual

17 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M787, F66 (LHD models)
IHarness for open or short between ECM and ECM relay
ERepair open circuit or short to ground or short to power in harness or connectors.
18 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminals 39, 43, 106, 112, 118 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OKEGO TO 20.
NGEGO TO 19.
19 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F108, E225
IHarness connectors M842, F135 (RHD models)
IHarness for open or short between ECM and engine ground
ERepair open circuit or short to ground or short to power in harness or connectors.
20 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-78.
EINSPECTION END
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-87

Component Description
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 wire that is supplied with
electric current from the ECM. The temperature of the hot wire is
controlled by the ECM a certain amount. The heat generated by the
hot wire 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 wire as air flow increases. The ECM
detects the air flow by means of this current change.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
MAS AIR/FL SEIEngine: After warming up
IAir conditioner switch: ªOFFº
IShift lever: Neutral position
INo-loadIdle 1.6 - 2.0V
ECM Terminals and Reference Value
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 damage the
ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
35 R Mass air flow sensorEngine is running.
Warm-up condition
Idle speed1.6 - 2.0V
49 W Sensor's power supply Ignition switch ªONº
Approximately 5V
50 B Sensor's groundEngine is running.
Warm-up condition
Idle speedApproximately 0V
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
IAn excessively high or low voltage from the sensor is sent to
ECM.IHarness or connectors
(The sensor circuit is open or shorted.)
IMass air flow sensor
SEF987W
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-88

DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº, and wait at least 6 seconds.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Start engine and wait at least 3 seconds.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-92.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº, and wait at least 6 seconds.
2) Start engine and wait at least 3 seconds.
3) Turn ignition switch ªOFFº, wait at least 5 seconds and then turn
ªONº.
4) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º with
ECM.
5) If DTC is detected, go to ªDiagnostic Procedureº, EC-92.
SEF817Y
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-89

Wiring Diagram
LHD MODELS
YEC173A
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-90

RHD MODELS
YEC174A
DTC 0102 MASS AIR FLOW SENZD30DDTi
Wiring Diagram (Cont'd)
EC-91

Diagnostic Procedure
1 CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect mass air flow sensor harness connector.
MEC993D
3. Turn ignition switch ªONº.
4. Check voltage between mass air flow sensor terminals 2, 4 and ground with CONSULT-II or tester.
MEC973D
MTBL1318
OK or NG
OKEGO TO 3.
NGEGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M787, F66 (LHD models)
IHarness connectors F135, M842 (RHD models)
IHarness for open or short between mass air flow sensor and ECM
IHarness for open or short between mass air flow sensor and ECM relay
ERepair open circuit or short to ground or short to power in harness or connector.
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-92

3 CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
MEC994D
3. Check harness continuity between mass air flow sensor terminal 3 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OKEGO TO 5.
NGEGO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F135, M842 (RHD models)
IHarness for open or short between mass air flow sensor and ECM
ERepair open circuit or short to ground or short to power in harness or connectors.
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 5 and ECM terminal 35. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OKEGO TO 7.
NGEGO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F135, M842 (RHD models)
IHarness for open or short between mass air flow sensor and ECM
ERepair open circuit or short to ground or short to power in harness or connectors.
DTC 0102 MASS AIR FLOW SENZD30DDTi
Diagnostic Procedure (Cont'd)
EC-93

7 CHECK 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 35 (Mass air flow sensor signal) and ground.
SEF400Y
4. If the voltage is out of specification, disconnect MAFS harness connector and connect it again.
Then repeat above check.
OK or NG
OKEGO TO 8.
NGEReplace mass air flow sensor.
8 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-78.
EINSPECTION END
DTC 0102 MASS AIR FLOW SENZD30DDTi
Diagnostic Procedure (Cont'd)
EC-94