Page 918 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-3
SYMPTOM CHARTM1141005600393
SYMPTOM PROCEDURES
INSPECTION PROCEDURE 1: Coolant Leak
DIAGNOSIS
STEP 1. Check for coolant leaks.
When pressure testing the cooling system, slowly
release cooling system pressure to avoid being
burned by hot coolant.
Be sure to completely clean away any moisture from
the places checked.
When the tester is removed, be careful not to spill any
coolant.
When installing and removing the tester and when test-
ing, be careful not to deform the filler neck of the radia-
tor.
Check that the coolant level is up to the filler neck. Install a radi-
ator tester and apply 160 kPa (23 psi) pressure, and then check
for leakage from the radiator hose or connections.
Q: Is leakage present from the radiator hose or
connections?
YES : Repair or replace the appropriate part, then go to
St e p 2 .
NO : There is no action to be taken.
STEP 2. Retest the system.
Q: Is there still coolant leakage?
YES : Return to Step 1.
NO : The procedure is complete. SYMPTOM INSPECTION
PROCEDUREREFERENCE
PA G E
Coolant leak 1
14-3
Engine overheating 2
14-4
Radiator fan and condenser fan do not operate 3
14-4
Radiator fan and condenser fan do not change speed or stop 4
14-20
Radiator fan does not operate 5
14-25
Condenser fan does not operate 6
14-25
Page 919 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-4
INSPECTION PROCEDURE 2: Engine Overheating
DIAGNOSIS
STEP 1. Remove the radiator cap and check for coolant
contamination.
Q: Is the coolant contaminated with rust and oil?
YES : Replace it. Refer to P.14-27.
NO : There is no action to be taken. Go to Step 2.
STEP 2. Check the radiator cap valve opening pressure.
NOTE: Be sure that the cap is clean before testing. Rust or
other foreign material on the cap seal will cause an improper
reading.
(1) Use a cap adapter to attach the cap to the tester.
(2) Increase the pressure until the gauge indicator stops
moving.
Minimum limit: 83 kPa (12 psi)
Standard value: 93
123 kPa (14 18 psi)
Q: Does the reading remain at or above the minimum limit?
YES : Go to Step 3.
NO : Replace the radiator cap. Then go to Step 5.
STEP 3. Check thermostat operation.
Refer to 38.
Q: Does the thermostat operate correctly?
YES : Go to Step 4.
NO : Replace the thermostat, then go to Step 5.
STEP 4. Check the drive belt for slippage or damage.
Refer to GROUP 00, Maintenance Service
Drive Belts
(Check Condition). <3.8L Engine>39 .
Q: Is the drive belt loose or damaged?
YES : Adjust or replace the drive belt, then go to Step 5.
NO : There is no action to be taken.
STEP 5. Retest the system.
Check the engine coolant temperature.
Q: Is the engine coolant temperature abnormally high?
YES : Return to Step 2.
NO : The procedure is complete.
Page 920 of 1500
Page 935 of 1500
Page 940 of 1500
ENGINE COOLING DIAGNOSIS
ENGINE COOLING14-25
STEP 7. MUT-III self-diag code
Check if an MPI system self-diag code is set. (Refer to GROUP
13A - Trouble shooting 13A-5)
Q: Diagnosis code set?
YES : Inspection chart for diagnosis code (Refer to GROUP
13A - Trouble shooting 13A-5)
NO : Replace the engine-ECU (Refer to GROUP 13A,
Engine-ECU 13A-675 ) Then go to Step 8 .
STEP 8. Check the symptoms.
Q: Does the radiator fan motor and the condenser fan
motor operate correctly?
YES : This symptom is complete.
NO : Return to Step 1.
INSPECTION PROCEDURE 5: Radiator Fan does not Operate
.
Radiator Fan and Condenser Fan Drive
Circuit
.
TECHNICAL DESCRIPTION
The cause could be a malfunction of the radiator fan
motor or an open circuit between the fan controller
and the radiator fan motor.
.
TROUBLESHOOTING HINTS
Malfunction of radiator fan motor
Malfunction of fan controller
Refer to component locations GROUP-1
Refer to configuration diagrams GROUP-1
Refer to circuit diagrams GROUP-1
DIAGNOSIS
Replace the radiator fan motor and fan controller assembly.
Q: Does the radiator fan operate correctly?
YES : There is no action to be taken?
NO : Repair the wiring harness between the fan controller
and the radiator fan motor.
INSPECTION PROCEDURE 6: Condenser Fan does not Operate
.
Radiator Fan and Condenser Fan Drive
Circuit
.
TECHNICAL DESCRIPTION
The cause could be a malfunction of the condenser
fan motor or fan controller.
.
TROUBLESHOOTING HINTS
Malfunction of condenser fan motor
Malfunction of fan controller
Refer to component locations GROUP-1
Refer to configuration diagrams GROUP-1
Refer to circuit diagrams GROUP-1
Page 941 of 1500
ON-VEHICLE SERVICE
ENGINE COOLING14-26
DIAGNOSIS
STEP 1. Check the condenser fan motor.
Condenser fan motor check. (Refer to GROUP 55, Condenser
and Condenser Fan Motor.
Q: Is the condenser fan motor in good condition?
YES : Go to Step 2.
NO : Replace the condenser fan motor, then go to Step 3.
STEP 2. Check the fan controller.
Refer to 29.
Q: Is the fan controller in good condition?
YES : Go to Step 3.
NO : Replace the fan motor and fan controller (Refer to
14-25). Then go to Step 3.
STEP 3. Check the symptoms.
Q: Do the condenser fan operate?
YES : This symptom is complete.
NO : Return to Step 1.
ON-VEHICLE SERVICE
ENGINE COOLANT LEAK CHECKM1141001000333
When pressure testing the cooling system, slowly
release cooling system pressure to avoid getting
burned by hot coolant.
Be sure to completely clean away any moisture from
the places checked.
When the tester is taken out, be careful not to spill any
coolant.
Be careful when installing and removing the tester and
when testing not to deform the filler neck of the radia-
tor.
1. Check that the coolant level is up to the filler neck. Install a
radiator tester and apply 160 kPa (23 psi) pressure, and
then check for leakage from the radiator hose or
connections.
2. If there is leakage, repair or replace the appropriate part.
Page 942 of 1500
ON-VEHICLE SERVICE
ENGINE COOLING14-27
RADIATOR CAP PRESSURE CHECKM1141001300419
NOTE: Be sure that the cap is clean before testing. Rust or
other foreign material on the cap seal will cause an improper
reading.
1. Use a cap adapter to attach the cap to the tester.
2. Increase the pressure until the indicator of the gauge stops
moving.
Minimum limit: 83 kPa (12 psi)
Standard value: 93
123 kPa (14 18 psi)
3. Replace the radiator cap if the reading does not remain at or
above the limit.
ENGINE COOLANT REPLACEMENTM1141001200478
When removing the radiator cap, use care to avoid
contact with hot coolant or steam. Place a shop towel
over the cap and turn the cap counterclockwise a lit-
tle to let the pressure escape through the vinyl tube.
After relieving the steam pressure, remove the cap by
slowly turning it counterclockwise.
1. Drain the water from the radiator, heater core and engine
after unplugging the radiator drain plug and removing the
radiator cap.
Page 943 of 1500
ON-VEHICLE SERVICE
ENGINE COOLING14-28
2. Drain the water in the water jacket by unplugging the drain
plug of the cylinder block.
3. Remove the radiator condenser tank assembly and drain the
coolant.
4. Drain the coolant then clean the path of the coolant by
injecting water into the radiator from the radiator cap area.
5. Apply the designated sealant to the screw area of the
cylinder block drain plug, and then tighten to the standard
torque.
Specified sealant: 3M
AAD Part No.8731 or equiva-
lent
Tightening torque:
39
5 Nm
6. Securely tighten the radiator drain plug.
7. Assemble the radiator condenser tank assembly.
