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

id0103d5802400

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 water temperature gauge

―  ECT sensor malfunction

―  Instrument cluster malfunction

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 water temperature gauge ― 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.
1		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”. (See NO.9 FAST IDLE/RUNS ON [MZR 2.0 DISI].)
2	Does the engine speed continue at fast idle?	No	Go to the next step.
3	Perform the Cooling Fan Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [MZR 2.0 DISI].) Does the cooling fan control system operate properly?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning part according to the inspection results.
4	Cool down the engine. Remove the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION [MZR 2.0 DISI].) Inspect the thermostat operation. (See THERMOSTAT INSPECTION [MZR 2.0 DISI].) Is there any malfunction?	Yes	Replace the thermostat. (See THERMOSTAT REMOVAL/INSTALLATION [MZR 2.0 DISI].)
4		No	Inspect the water temperature gauge. (See INSTRUMENT CLUSTER INSPECTION.) • If there is any malfunction: ― Repair or replace the malfunctioning part according to the inspection results. • If there is no malfunction: ― Inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [MZR 2.0 DISI].) ― Replace the ECT sensor if necessary. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [MZR 2.0 DISI].)
5	Verify the test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [MZR 2.0 DISI].) • 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].)