2000 NISSAN PATROL relay

7 CHECK ECM POWER SUPPLY CIRCUIT-III
1. Disconnect ECM relay.
SEF225Z
2. Check voltage between relay terminals 1, 3 and ground with CONSULT-II or tester.
SEF289Z
OK or NG
OKcGO TO 9.
NGcGO TO 8.
8 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E104, M86 or E127, M21
+20A fuse
+Harness for open or short between ECM relay and battery
cRepair open circuit or short to ground or short to power in harness or connectors.
9 CHECK OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 4 and ECM relay terminal 2. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 11.
NGcGO TO 10.
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-1082

10 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M52, F7
+Harness for open or short between ECM and ECM relay
cRepair open circuit or short to ground or short to power in harness or connectors.
11 CHECK ECM POWER SUPPLY CIRCUIT-IV
1. Check harness continuity between ECM terminals 56, 61, 116 and ECM relay terminal 5. Refer to Wiring Diagram.
Continuity should exist.
2. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 13.
NGcGO TO 12.
12 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M50, F5
+Harness for open or short between ECM and ECM relay
cRepair open circuit or short to ground or short to power in harness or connectors.
13 CHECK ECM RELAY
1. Apply 12V direct current between ECM relay terminals 1 and 2.
2. Check continuity between ECM relay terminals 3 and 5, 7 and 6.
SEF296X
OK or NG
OKcGO TO 14.
NGcReplace ECM relay.
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-1083

14 CHECK ECM POWER SUPPLY CIRCUIT-V
1. Reconnect all harness connectors disconnected.
2. Turn ignition switch ªONº.
3. Check voltage between ECM terminal 102 and ground with CONSULT-II or tester.
SEF290Z
OK or NG
OKcGO TO 16.
NGcGO TO 15.
15 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M52, F7
+Fuse block (J/B) connector M2
+10A fuse
+Harness for open or short between ECM and fuse
cRepair open circuit or short to ground or short to power in harness or connectors.
16 CHECK ECM POWER SUPPLY CIRCUIT-VI
1. Turn ignition switch ªOFFº.
2. Disconnect ECM relay.
SEF225Z
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminals 56, 61, 116 and ECM relay terminal 5. Refer to Wiring Diagram.
Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 18.
NGcGO TO 17.
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-1084

17 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M50, F5
+Harness for open or short between ECM and ECM relay
cRepair 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
OKcGO TO 20.
NGcGO TO 19.
19 DETECT MALFUNCTIONING PART
Check the following.
+Joint connector-3
+Harness for open or short between ECM and engine ground
cRepair 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-1076.
cINSPECTION END
TROUBLE DIAGNOSIS FOR POWER SUPPLYZD30DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-1085

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

Description
SYSTEM DESCRIPTION
Sensor Input signal to ECM ECM function Actuator
Vehicle speed sensor Vehicle speed
Cooling fan con-
trolCooling fan relay Engine coolant temperature sensor Engine coolant temperature
Air conditioner switch Air conditioner ªONº signal
The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, air con-
ditioner ON signal. The control system has 2-step control [ON/OFF].
OPERATION
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND SIG+Engine: After warming up, idle
the engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
COOLING FAN+When cooling fan is stopped. OFF
+When cooling fan operates. ON
SEF450Z
DTC 0208 OVER HEATZD30DDTi
EC-1105

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)
14 L Cooling fan relayEngine is running.
Cooling fan is not operatingBATTERY VOLTAGE
(11 - 14V)
Engine is running.
Cooling fan is operatingApproximately 0.1V
On Board Diagnosis Logic
This diagnosis continuously monitors the engine coolant temperature.
If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.
Malfunction is detected when ... Check Items (Possible Cause)
+Cooling fan does not operate properly (Overheat).
+Cooling fan system does not operate properly (Overheat).
+Engine coolant was not added to the system using the proper
filling method.+Harness or connectors
(The cooling fan circuit is open or shorted.)
+Cooling fan
+Radiator hose
+Radiator
+Radiator cap
+Water pump
+Thermostat
+Fan belt
+Engine coolant temperature sensor
For more information, refer to ªMAIN 12 CAUSES OF
OVERHEATINGº, EC-1116.
CAUTION:
When a malfunction is indicated, be sure to replace the coolant following the procedure in the MA
section (ªChanging Engine Coolantº, ªENGINE MAINTENANCEº). Also, replace the engine oil.
1) Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure
to use coolant with the proper mixture ratio. Refer to MA section (ªAnti-freeze Coolant Mixture
Ratioº, ªRECOMMENDED LUBRICANTS AND FLUIDSº).
2) After refilling coolant, run engine to ensure that no water-flow noise is emitted.
DTC 0208 OVER HEATZD30DDTi
EC-1106

4 CHECK COOLING FAN POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan relay-1.
SEF690V
3. Turn ignition switch ªONº.
4. Check voltage between cooling fan relay-1 terminals 2, 5 and ground with CONSULT-II or tester.
SEF291Z
OK or NG
OKcGO TO 6.
NGcGO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
+Fuse block (J/B) connector E112
+10A fuse or 20A fuse
+30A fusible links
+Harness for open or short between cooling fan relay-1 and fuse
+Harness for open or short between cooling fan relay-1 and battery
cRepair open circuit or short to ground or short to power in harness or connectors.
DTC 0208 OVER HEATZD30DDTi
Diagnostic Procedure (Cont'd)
EC-1111