NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)]

id0103q5802400

18

COOLING SYSTEM CONCERNS-RUNS COLD
DESCRIPTION
•  Engine does not reach normal operating temperature.
POSSIBLE CAUSE
•  Improper indication of low engine coolant temperature indicator light and/or high engine coolant temperature warning light
―  ECT sensor malfunction
―  Instrument cluster malfunction
•  Cooling fan system malfunction
•  Condenser fan system malfunction
•  Coolant control valve malfunction
•  Foreign matter penetration in engine coolant

Caution
•  Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.

Related PIDs

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)
ECT
°C, °F
Engine coolant temperature
•  Displays ECT
V
•  ECT is 20 °C {68 °F}: Approx. 3.10 V
•  ECT is 40 °C {104 °F}: Approx. 2.16 V
•  ECT is 60 °C {140 °F}: Approx. 1.40 V
•  ECT is 80 °C {176 °F}: Approx. 0.87 V
•  ECT is 100 °C {212 °F}: Approx. 0.54 V

Diagnostic Procedure

STEP

INSPECTION

RESULTS

ACTION
1
DETERMINE IF MALFUNCTION CAUSE IS HVAC SYSTEM OR ENGINE
•  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
VERIFY IDLE SPEED
•  Does the engine speed continue at fast idle?
Yes
Perform the symptom troubleshooting “NO.9 FAST IDLE/RUNS ON”.
(See NO.9 FAST IDLE/RUNS ON [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)].)
No
Go to the next step.
3
INSPECT ECT SENSOR SIGNAL
•  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.
(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)].)
•  If there is any malfunction:
―  Replace the ECT sensor.
•  If there is no malfunction:
―  Perform the instrument cluster symptom troubleshooting “LOW ENGINE COOLANT TEMPERATURE INDICATOR LIGHT/HIGH ENGINE COOLANT TEMPERATURE WARNING LIGHT ILLUMINATES OR FLASHES CONTINUOUSLY”.
4
INSPECT COOLING FAN CONTROL SYSTEM OPERATION
•  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.
5
INSPECT COOLANT CONTROL VALVE
•  Cool down the engine.
•  Inspect the coolant control valve operation.
•  Is there any malfunction?
Yes
Replace the coolant control valve.
(See COOLANT CONTROL VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)].)
No
Reinstall the coolant control valve, then go to the next step.
(See COOLANT CONTROL VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)].)
6
VERIFY THAT NO FOREIGN MATTER IS IN ENGINE COOLANT
•  Drain the engine coolant.
•  Has foreign matter penetrated the engine coolant?
Yes
Replace the engine coolant.
(See ENGINE COOLANT REPLACEMENT [SKYACTIV-G 2.5 (WITH CYLINDER DEACTIVATION)].)
No
Go to the next step.
7
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform 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.