2000 NISSAN PATROL ecm

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

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

Description
The vehicle speed sensor is installed in the transaxle. It contains
a pulse generator which provides a vehicle speed signal to the
speedometer. The speedometer then sends a signal to the ECM.
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 CONDITIONDATA (DC Voltage and
Pulse Signal)
26 L/OR Vehicle speed sensorEngine is running.
Lift up the vehicle
In 1st gear position
Vehicle speed is 10 km/h (6 MPH)0 - Approximately 4.8V
SEF257Z
Engine is running.
Lift up the vehicle
In 2nd gear position
Vehicle speed is 30 km/h (19 MPH)Approximately 2.2V
SEF258Z
On Board Diagnosis Logic
Malfunction is detected when .... Check Items (Possible Cause)
+The almost 0 km/h (0 MPH) signal from vehicle speed sensor
is sent to ECM even when vehicle is being driven.+Harness or connector
(The vehicle speed sensor circuit is open or shorted.)
+Vehicle speed sensor
AEC110
DTC 0104 VEHICLE SPEED SENZD30DDTi
EC-1096

Overall Function Check
Use this procedure to check the overall function of the vehicle
speed sensor circuit. During this check, a DTC might not be
confirmed.
WITH CONSULT-II
1) Lift up the vehicle.
2) Start engine.
3) Read vehicle speed sensor signal in ªDATA MONITORº
mode with CONSULT-II.
The vehicle speed on CONSULT-II should be able to
exceed 10 km/h (6 MPH) when rotating wheels with suit-
able gear position.
4) If NG, go to ªDiagnostic Procedureº, EC-1099.
WITHOUT CONSULT-II
1) Lift up the vehicle.
2) Start engine.
3) Rotate drive wheel by hand.
4) Check voltage between ECM terminal 26 and ground with
tester.
Voltage should vary between 0 - 4.8V.
5) If NG, go to ªDiagnostic Procedureº, EC-1099.
SEF864Y
SEF811R
DTC 0104 VEHICLE SPEED SENZD30DDTi
EC-1097

Diagnostic Procedure
1 CHECK VEHICLE SPEED SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector and combination meter harness connector.
3. Check harness continuity between ECM terminal 26 and combination meter terminal 26. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 3.
NGcGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M52, F7
+Joint connector-1
+Harness for open or short between ECM and combination meter
cRepair open circuit or short to ground or short to power in harness or connectors.
3 CHECK SPEEDOMETER FUNCTION
Make sure that speedometer functions properly.
OK or NG
OKcGO TO 5.
NGcGO TO 4.
4 CHECK SPEEDOMETER CIRCUIT FOR OPEN AND SHORT
Check the following.
+Harness connectors E70, E201
+Harness connectors M86, E104 or M21, E127
+Harness for open or short between combination meter and vehicle speed sensor
OK or NG
OKcCheck vehicle speed sensor and combination meter. Refer to EL section.
NGcRepair open circuit or short to ground or short to power in harness or connectors.
5 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-1076.
cINSPECTION END
DTC 0104 VEHICLE SPEED SENZD30DDTi
EC-1099

Description
The accelerator switch is installed to the accelerator pedal
assembly. The switch senses accelerator position and sends an
ON-OFF signal to the ECM. The ECM uses the signal to control
the fuel cut operation at deceleration for better fuel efficiency.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
ACCEL SW (FC)+Ignition switch: ON
(Engine stopped)Accelerator pedal: fully released CLOSE
Accelerator pedal: slightly open OPEN
DECELER F/CUT+Engine: After warming up Idle OFF
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)
29 R/L Accelerator switch (F/C)Ignition switch ªONº
Accelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
Ignition switch ªONº
Accelerator pedal depressedApproximately 0V
On Board Diagnosis Logic
Malfunction is detected when .... Check Items (Possible Cause)
+The OFF signal (short) is sent to the ECM for a certain period
of time even when the accelerator pedal is not being
depressed.+Harness or connectors
(The switch circuit is shorted.)
+Accelerator switch (F/C)
SEF687V
DTC 0203 ACCEL POS SW (F/C)ZD30DDTi
EC-1100