NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [L3 Turbo]SM2444518
NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [L3 Turbo]

id0103b4802400

18

COOLING SYSTEM CONCERNS—RUNS COLD
DESCRIPTION
• Engine does not reach normal operating temperature.
POSSIBLE CAUSE
• Thermostat malfunction
• Condenser fan system malfunction
• Cooling fan system 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.
• If there is any malfunction:
― 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”.
(See NO.9 FAST IDLE/RUNS ON [L3 Turbo].)
No
Go to the next step.
3
Cool down the engine.
Remove the thermostat.
(See THERMOSTAT REMOVAL/INSTALLATION [L3 Turbo].)
Inspect the thermostat.
(See THERMOSTAT INSPECTION [L3 Turbo].)
Is there any malfunction?
Yes
Replace the thermostat.
(See THERMOSTAT REMOVAL/INSTALLATION [L3 Turbo].)
No
Reinstall the thermostat, then go to the next step.
(See THERMOSTAT REMOVAL/INSTALLATION [L3 Turbo].)
4
Perform the Cooling Fan Control System Inspection.
(See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L3 Turbo].)
Does the cooling fan system operate properly?
Yes
Access the ECT PID using the M-MDS.
(See ON-BOARD DIAGNOSTIC TEST [L3 Turbo].)
Inspect for both ECT PID and temperature gauge readings.
• If the temperature gauge on instrument cluster indicates normal but the ECT PID is not same as temperature gauge reading:
― Inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [L3 Turbo].)
― Replace the ECT sensor, if necessary. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR REMOVAL/INSTALLATION [L3 Turbo].)
• If the temperature gauge on instrument cluster indicates overheating but the ECT PID is normal:
― Inspect the instrument cluster. (See INSTRUMENT CLUSTER INSPECTION.)
― Replace the instrument cluster, if necessary. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION.)
No
Repair or replace the malfunctioning part according to the inspection results.
5
Verify test results.
• If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [L3 Turbo].)
• 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.