NO.11 COOLING SYSTEM CONCERNS-OVERHEATING [MZ-CD 1.6]

id0103e4854400

11

Cooling system concerns-Overheating
DESCRIPTION
•  Engine overheats (signs of coolant boiling)
POSSIBLE CAUSE
•  Cooling system related DTC is detected.
•  Radiator malfunction
•  Cooling system does not hold pressure.
•  Coolant expansion tank cap or seal improper.
•  Coolant expansion tank malfunction.
•  Coolant level improper
•  Contaminated engine coolant condition.
•  Radiator grille improper installation
•  Coolant concentration improper.
•  Engine internal malfunction (coolant passage blocked)
•  Cooling fan motor malfunction
•  Air in cooling system
•  Water pump malfunction
•  Improper indication of low engine coolant temperature indicator light
―  ECT sensor malfunction
―  Instrument cluster malfunction
•  Thermostat malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION
1
VERIFY PCM DTC
•  Perform the PCM DTC inspection using the M-MDS.
•  Are any cooling system related DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [MZ-CD 1.6].)
No
Go to the next step.
2
VISUALLY INSPECT RELATED PART CONDITION
•  Visually inspect the following:
Mechanical:
―  Coolant leak(s)
―  Coolant level
―  Gaskets/seals
―  Hose(s)/hose joints
―  Coolant expansion tank cap and seal
―  Coolant expansion tank
―  Radiator
―  Water pump
―  Thermostat
―  Thermostat housing
―  Radiator grille installation
Electrical:
―  Fuse(s)
―  Relay(s)
―  Electrical connector(s) (PCM, ECT sensor, cooling fan motor)
―  Cooling fan motor
―  ECT sensor
―  Wiring harness
•  Is there any malfunction?
Yes
Repair or replace the malfunctioning part according to the inspection results.
Repeat Step 2.
No
Go to the next step.
3
INSPECT ENGINE COOLANT CONCENTRATION
•  Perform the ENGINE COOLANT PROTECTION INSPECTION.
•  Is the engine coolant protection level correct?
Yes
Go to the next step.
No
Add water or engine coolant as necessary.
(See ENGINE COOLANT REPLACEMENT [MZ-CD 1.6].)
4
INSPECT FOR ENGINE COOLANT LEAKAGE
•  Perform the ENGINE COOLANT LEAKAGE INSPECTION.
•  Is there any leakage detected?
Yes
Repair or replace the applicable part.
No
Go to the next step.
5
INSPECT COOLING FAN RELAY
•  Inspect the cooling fan relays.
•  Are cooling fan relays normal?
Yes
Go to the next step.
No
Replace suspect relay.
6
INSPECT COOLING FAN MOTOR
•  Inspect the cooling fan motor.
•  Is the cooling fan motor normal?
Yes
Go to the next step.
No
Replace the cooling fan motor.
(See COOLING FAN MOTOR REMOVAL/INSTALLATION [MZ-CD 1.6].)
7
DETERMINE IF MALFUNCTION CAUSE IS AIR INGRESS IN COOLING SYSTEM OR OTHER
•  Perform the cooling system air bleeding.
•  Is the symptom solved?
Yes
Troubleshooting is completed.
(Air ingress into the cooling system.)
No
Go to the next step.
8
INSPECT ECT SENSOR SIGNAL
•  Access the ECT PID using the M-MDS.
•  Compare the ECT PID and low engine coolant temperature indicator light on instrument cluster condition.
•  Is the ECT PID value same as indicator light readings?
Yes
Go to the next step.
No
Go to the symptom troubleshooting “NO.9 Low engine coolant temperature indicator light/high engine coolant temperature warning light illuminates or flashes continuously”.
(See NO. 9 LOW ENGINE COOLANT TEMPERATURE INDICATOR LIGHT/HIGH ENGINE COOLANT TEMPERATURE WARNING LIGHT ILLUMINATES OR FLASHES CONTINUOUSLY [INSTRUMENT CLUSTER].)
9
INSPECT WATER PUMP
•  Cool down the engine.
•  Remove the water pump.
•  Visually inspect water pump.
•  Is there any malfunction detected?
Yes
Replace the water pump.
No
Replace the thermostat.
(See THERMOSTAT REMOVAL/INSTALLATION [MZ-CD 1.6].)
10
Verify test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If the malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.