NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [AJ (3.0L Duratec)]


18	Cooling system concerns-runs cold
DESCRIPTION	• Engine takes excessive period for reaching normal operating temperature.
POSSIBLE CAUSE	• Thermostat malfunction • Condenser fan system malfunction • Cooling fan system malfunction


STEP	INSPECTION	RESULTS	ACTION
1	• Is customer complaint "Lack of passenger compartment heat" only?	Yes	Inspect A/C and heater systems.
1		No	Go to the next step.
2	• Does engine speed continue at fast idle?	Yes	Go to symptom troubleshooting "No.9 Fast idle/runs on".
2	• Does engine speed continue at fast idle?	No	Go to the next step.
3	• Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [AJ (3.0L Duratec)].) (See THERMOSTAT INSPECTION [YF (2.0L Zetec), AJ (3.0L Duratec)].) • Is thermostat okay?	Yes	Access ECT PID on WDS or equivalent. Inspect both ECT PID and temperature gauge on instrument cluster readings. • If temperature gauge on instrument cluster indicates normal range but ECT PID is not same as temperature gauge reading, inspect ECT sensor. • If temperature gauge on instrument cluster indicates cold range but ECT PID is normal, inspect temperature gauge and heat gauge unit.
3		No	Replace thermostat.
4	• Verify test results. - If okay, return to diagnostic index to service any additional symptoms. - If malfunction remains, inspect related Service Information and perform repair or diagnosis. • If vehicle is repaired, troubleshooting completed. • If vehicle is not repaired or additional diagnostic information is not available, replace PCM.