Page 801 of 3051
Wiring DiagramNLEC0490MODELS WITH FUSE AND FUSIBLE LINK BOX E43NLEC0490S03
YEC682
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Wiring Diagram
EC-376
Page 802 of 3051
MODELS WITH FUSE AND FUSIBLE LINK BOX E90NLEC0490S04
YEC890
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Wiring Diagram (Cont'd)
EC-377
Page 803 of 3051
Diagnostic ProcedureNLEC0491
1 CHECK COOLING FAN OPERATION
1. Start engine and let it idle.
2. Set temperature lever at full cold position.
3. Turn air conditioner switch ªONº.
4. Turn blower fan switch ªONº.
5. Make sure that cooling fans-1 and -2 operate.
SEC163BA
OK or NG
OK©GO TO 11.
NG©GO TO 2.
2 CHECK AIR CONDITIONER OPERATION
Is air conditioner operating?
(Check operation of compressor and blower motor.)
OK or NG
OK©GO TO 3.
NG©Check for failure of air conditioner to operate. Refer to HA section.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Diagnostic Procedure
EC-378
Page 804 of 3051
3 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan relay.
SEF628Y
3. Turn ignition switch ªONº.
4. Check voltage between terminals 1, 3, 6 and ground with CONSULT-II or tester.
SEF590X
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
+10A fuse
+30A fusible link
+Harness for open or short between cooling fan relay and fuse
©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Diagnostic Procedure (Cont'd)
EC-379
Page 805 of 3051

5 CHECK GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect cooling fan motor-1 harness connector and cooling fan motor-2 harness connector.
SEF609Y
3. Check harness continuity between relay terminal 5 and motor-1 terminal 1, motor-1 terminal 2 and body ground.
Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to power.
5. Check harness continuity between relay terminal 7 and motor-2 terminal 1, motor-2 terminal 2 and body ground.
Refer to wiring diagram.
Continuity should exist.
6. Also check harness for short to power.
OK or NG
OK©GO TO 6.
NG©Repair open circuit or short to power in harness or connectors.
6 CHECK OUTPUT SIGNAL CIRCUIT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 13 and 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
OK©GO TO 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E76, F36
+Harness for open or short between cooling fan relay and ECM
©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK COOLING FAN RELAY
Refer to ªComponent Inspectionº, EC-384.
OK or NG
OK©GO TO 9.
NG©Replace cooling fan relay.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Diagnostic Procedure (Cont'd)
EC-380
Page 806 of 3051
9 CHECK COOLING FAN MOTORS-1 AND -2
Refer to ªComponent Inspectionº, EC-384.
OK or NG
OK©GO TO 10.
NG©Replace cooling fan motors.
10 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-145.
©INSPECTION END
11 CHECK COOLING SYSTEM FOR LEAK
Apply pressure to the cooling system with a tester, and check if the pressure drops.
Testing pressure: 157 kPa (1.57 bar, 1.6 kg/cm2, 23 psi)
CAUTION:
Higher than the specified pressure may cause radiator damage.
SLC754A
Pressure should not drop.
OK or NG
OK©GO TO 12.
NG©Check the following for leak
+Hose
+Radiator
+Water pump
Refer to LC-14, ªWater Pumpº.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Diagnostic Procedure (Cont'd)
EC-381
Page 807 of 3051
12 CHECK RADIATOR CAP
Apply pressure to cap with a tester.
SLC755A
Radiator cap relief pressure:
59 - 98 kPa (0.59 - 0.98 bar, 0.6 - 1.0 kg/cm2,9-14psi)
OK or NG
OK©GO TO 13.
NG©Replace radiator cap.
13 CHECK THERMOSTAT
1. Check valve seating condition at normal room temperatures.
It should seat tightly.
2. Check valve opening temperature and valve lift.
SLC343
Valve opening temperature:
82ÉC (180ÉF) [standard]
Valve lift:
More than 8 mm/95ÉC (0.31 in/203ÉF)
3. Check if valve is closed at 5ÉC (9ÉF) below valve opening temperature.
For details, refer to LC section (ªThermostatº).
OK or NG
OK©GO TO 14.
NG©Replace thermostat
14 CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to ªCOMPONENT INSPECTIONº, EC-174.
OK or NG
OK©GO TO 15.
NG©Replace engine coolant temperature sensor.
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Diagnostic Procedure (Cont'd)
EC-382
Page 808 of 3051
15 CHECK MAIN 12 CAUSES
If the cause cannot be isolated, go to ªMAIN 12 CAUSES OF OVERHEATINGº, EC-384.
©INSPECTION END
DTC P1217 OVERHEAT (COOLING SYSTEM)QG18DE
Diagnostic Procedure (Cont'd)
EC-383