NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [MZR 2.0 DISI i-stop]


id0103d3802400

18

COOLING SYSTEM CONCERNS-RUNS COLD

DESCRIPTION
•  Engine does not reach normal operating temperature.
POSSIBLE CAUSE
•  Condenser fan system malfunction
•  Thermostat malfunction
•  Cooling fan system malfunction
•  Improper indication of low engine coolant temperature indicator light and/or high engine coolant temperature warning light
―  ECT sensor malfunction
―  Instrument cluster malfunction

Diagnostic procedure

STEP

INSPECTION

RESULTS

ACTION

1
Is a customer complaint “Lack of passenger compartment heat” only?
Yes
Inspect the A/C heater system.
Repair or replace the malfunctioning part according to the inspection results.
No
Go to the next step.
2
Does the engine speed continue at fast idle?
Yes
Perform the symptom troubleshooting “NO.9 FAST IDLE/RUNS ON”.
No
Go to the next step.
3
Perform the Cooling Fan Control System Inspection.
Does the cooling fan control system operate properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results.
4
Cool down the engine.
Remove the thermostat.
Inspect the thermostat operation.
Is there any malfunction?
Yes
Replace the thermostat.
No
Reinstall the thermostat, then go to the next step.
5
Access the ECT PID using the M-MDS.
Compare the ECT PID and low engine coolant temperature indicator light and high engine coolant temperature warning light operation.
Is the ECT PID value same as indicator/warning light readings?
Yes
Go to the next step.
No
Inspect the ECT sensor.
•  If there is any malfunction:
•  If there is no malfunction:
―  Perform the instrument cluster symptom troubleshooting “NO. 10 LOW ENGINE COOLANT TEMPERATURE INDICATOR LIGHT/HIGH ENGINE COOLANT TEMPERATURE WARNING LIGHT ILLUMINATES OR FLASHES CONTINUOUSLY”.
6
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0 DISI i-stop].)
•  If a 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, replace the PCM. (See PCM REMOVAL/INSTALLATION [MZR 2.0 DISI i-stop].)