2001 NISSAN PICK-UP relay

10 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E101, M5
+Harness connectors M48, F54 (RHD models)
+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 and ECM relay terminal 6. 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 E101, M5
+Harness connectors M47, F55 (RHD models)
+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 18.
NGcReplace ECM relay.
TROUBLE DIAGNOSIS FOR POWER SUPPLYYD25DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-3478

14 CHECK ECM POWER SUPPLY CIRCUIT-V
1. Turn ignition switch ªOFFº.
2. Disconnect ECM relay.
SEC950C
3. Disconnect ECM harness connector.
4. Check harness continuity between ECM terminals 56, 61 and ECM relay terminal 6. Refer to Wiring Diagram.
Continuity should exist.
5. Also check harness for short to ground and short to power.
OK or NG
OKcGO TO 16.
NGcGO TO 15.
15 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M101, M5
+Harness connectors M47, F55 (RHD models)
+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.
16 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 18.
NGcGO TO 17.
17 DETECT MALFUNCTIONING PART
Check 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.
18 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3469.
cINSPECTION END
TROUBLE DIAGNOSIS FOR POWER SUPPLYYD25DDTi
Main Power Supply and Ground Circuit
(Cont'd)
EC-3479

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. The
control system has 2-step control [ON/OFF].
OPERATION
*: Refer to HA section.
CONSULT-II Reference Value in Data Monitor
Mode
Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
AIR COND RLY+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
SEC242D
DTC 0208 OVER HEATYD25DDTi
EC-3489

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 G/B 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-3501.
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 HEATYD25DDTi
EC-3490

4 CHECK COOLING FAN POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan relay.
SEC954C
3. Turn ignition switch ªONº.
4. Check voltage between cooling fan relay terminals 2, 5 and ground with CONSULT-II or tester.
SEC161D
OK or NG
OKcGO TO 6.
NGcGO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M5, E101
+10A fuse
+30A fusible link
+Harness for open or short between cooling fan relay and fuse
+Harness for open or short between cooling fan relay and battery
cRepair open circuit or short to ground or short to power in harness or connectors.
DTC 0208 OVER HEATYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3495

6 CHECK COOLING FAN GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan motor harness connector.
SEC232D
3. Check harness continuity between cooling fan relay terminal 3 and cooling fan motor terminals 1, cooling fan motor terminals 2
and body 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 7.
NGcRepair open circuit or short to ground or short to power in harness or connectors.
7 CHECK COOLING FAN OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Disconnect triple-pressure switch harness connector.
3. Check harness continuity between ECM terminal 14 and cooling fan relay terminal 1, cooling fan relay terminal 1 and triple-pres-
sure switch terminal 2, triple-pressure switch terminal 3 and 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 9.
NGcGO TO 8.
8 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M5, E101
+Harness connectors M47, F55 (RHD models)
+Harness for open or short between cooling fan relay and ECM
+Harness for open or short between cooling fan relay and triple-pressure switch
+Harness for open or short between triple-pressure switch and ground
cRepair open circuit or short to ground or short to power in harness or connectors.
DTC 0208 OVER HEATYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3496

9 CHECK COOLING FAN RELAY
Check continuity between cooling fan relay terminals 3 and 5 under the following conditions.
SEC340C
OK or NG
OKcGO TO 10.
NGcReplace cooling fan relay.
10 CHECK COOLING FAN MOTOR
Supply battery voltage between the following terminals and check operation.
SEC162D
OK or NG
OKcGO TO 11.
NGcReplace cooling fan motor.
11 CHECK TRIPLE PRESSURE SWITCH
Refer to HA section.
OK or NG
OKcGO TO 12.
NGcReplace triple pressure switch.
12 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3469.
cINSPECTION END
DTC 0208 OVER HEATYD25DDTi
Diagnostic Procedure (Cont'd)
EC-3497

Diagnostic Procedure
1 CHECK ELECTRONIC CONTROL FUEL INJECTION PUMP POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect electronic control fuel injection pump harness connector.
SEC228D
3. Turn ignition switch ªONº.
4. Check voltage between electronic control fuel injection pump terminal 7 and ground.
SEF438Y
OK or NG
OKcGO TO 3.
NGcGO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E30, E203
+Harness connectors E101, M5
+Harness connectors M47, F55 (RHD models)
+Harness for open or short between electronic control fuel injection pump and ECM
+Harness for open or short between electronic control fuel injection pump and ECM relay
cRepair open circuit or short to ground or short to power in harness or connectors.
3 CHECK ELECTRONIC CONTROL FUEL INJECTION PUMP GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between electronic control fuel injection pump terminal 6 and 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 0402 P9zFUEL TEMP SENYD25DDTi
EC-3513