2000 NISSAN PATROL Electronic Repair Manual

Wiring Diagram
TEC098M
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-1088

Diagnostic Procedure
1 CHECK MAFS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect mass air flow sensor harness connector.
SEF226Z
3. Turn ignition switch ªONº.
4. Check voltage between mass air flow sensor terminals 2, 4 and gund with CONSULT-II or tester.
SEF297X
OK or NG
OKcGO TO 3.
NGcGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E230, F12
+Harness connectors M50, F5
+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
cRepair open circuit or short to ground or short to power in harness or connector.
DTC 0102 MASS AIR FLOW SENZD30DDTi
EC-1089

3 CHECK MAFS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF227Z
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
OKcGO TO 5.
NGcGO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E230, F12
+Harness connectors M51, F6
+Harness connectors E106, M88
+Harness for open or short between mass air flow sensor and ECM
+Harness for open or short between mass air flow sensor and TCM (Transmission control module)
cRepair 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 1 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
OKcGO TO 7.
NGcGO TO 6.
6 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E230, F12
+Harness for open or short between mass air flow sensor and ECM
cRepair 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-1090

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
OKcGO TO 8.
NGcReplace mass air flow sensor.
8 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-1076.
cINSPECTION END
DTC 0102 MASS AIR FLOW SENZD30DDTi
Diagnostic Procedure (Cont'd)
EC-1091

Description
The engine coolant temperature sensor is used to detect the
engine coolant temperature. The sensor modifies a voltage sig-
nal 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 thermistor decreases as temperature
increases.

Engine coolant tempera-
ture ÉC (ÉF)Voltage* (V) Resistance (kW)
þ10 (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
*: These data are reference values and measured between ECM terminal 19
(Engine coolant temperature sensor) 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.
On Board Diagnosis Logic
Malfunction is detected when ... Check Items (Possible Cause)
+An excessively high or low voltage from the sensor is entered
to ECM.+Harness or connectors (The sensor circuit is open or shorted.)
+Engine coolant temperature sensor
DTC Confirmation Procedure
WITH CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Wait at least 5 seconds.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-1094.
WITHOUT CONSULT-II
1) Turn ignition switch ªONº and wait at least 5 seconds.
2) Turn ignition switch ªOFFº, wait at least 5 seconds and then
turn ªONº.
3) Perform ªDiagnostic Test Mode II (Self-diagnostic results)º
with ECM.
4) If DTC is detected, go to ªDiagnostic Procedureº, EC-1094.
SEF594K
SEF012P
SEF817Y
DTC 0103 COOLANT TEMP SENZD30DDTi
EC-1092

Wiring Diagram
TEC099M
DTC 0103 COOLANT TEMP SENZD30DDTi
EC-1093

Diagnostic Procedure
1 CHECK ECTS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect engine coolant temperature sensor harness connector.
SEF228Z
3. Turn ignition switch ªONº.
4. Check voltage between ECTS terminal 2 and ground with CONSULT-II or tester.
SEF401Y
OK or NG
OKcGO TO 3.
NGcGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E230, F12
+Harness for open or short between engine control temperature sensor and ECM
cRepair open circuit or short to ground or short to power in harness or connectors.
3 CHECK ECTS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between ECTS terminal 1 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 5.
NGcGO TO 4.
DTC 0103 COOLANT TEMP SENZD30DDTi
EC-1094

4 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E230, F12
+Harness connectors F6, M51
+Harness connectors M88, E106
+Harness for open or short between engine coolant temperature sensor and ECM
+Harness for open or short between engine coolant temperature sensor and TCM (Transmission control module)
cRepair open circuit or short to ground or short to power in harness or connectors.
5 CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Remove engine coolant temperature sensor from the engine.
2. Check resistance between ECTS terminals 1 and 2 as shown in the figure.
SEF304X
OK or NG
OKcGO TO 6.
NGcReplace engine coolant temperature sensor.
6 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-1076.
cINSPECTION END
DTC 0103 COOLANT TEMP SENZD30DDTi
Diagnostic Procedure (Cont'd)
EC-1095