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

id0103b4802400

18 | COOLING SYSTEM CONCERNS - RUNS COLD
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DESCRIPTION | Engine takes excessive time to reach normal operating temperature.
POSSIBLE CAUSE | • Thermostat malfunction • Condenser fan system malfunction • Cooling fan system malfunction

Diagnostic procedure

STEP | INSPECTION | RESULTS | ACTION
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1 | Is customer complaint "Lack of passenger compartment heat" only? | Yes | Inspect the A/C heater system.
No | Go to the next step.
2 | Does the engine speed continue at fast idle? | Yes | Go to 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 and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [L8, LF, L3, L3 Turbo].) (See THERMOSTAT INSPECTION [L8, LF, L3, L3 Turbo].) Is thermostat normal? | Yes | Go to the next step.
No | Replace the thermostat.
4 | Perform the Cooling Fan Control System Operation Inspection. (See Cooling Fan Control System Inspection.) Does the cooling fan system operate properly? | Yes | Access the ECT PID using the WDS or equivalent. Inspect for both ECT PID and temperature gauge readings. If the temperature gauge on instrument cluster indicates normal but ECT PID is not same as temperature gauge reading, inspect the ECT sensor. (See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION [L3 Turbo].) If the temperature gauge on instrument cluster indicates overheating but ECT PID is normal, inspect the instrument cluster. (See Water Temperature Gauge.)
No | Repair or replace malfunctioning part, according to inspection results.
5 | Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. • If a malfunction remains, inspect the related Service Bulletins and/or On-line Repair 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.