NO.18 COOLING SYSTEM CONCERNS-RUNS COLD [AJ]


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		ACTION
1	• Is customer complaint "Lack of passenger compartment heat" only?	Yes	Inspect the A/C and the heater systems.
1		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 [AJ].)
2	• Does the engine speed continue at fast idle?	No	Go to the next step.
3	• Remove the thermostat and inspect the operation. (See THERMOSTAT REMOVAL/INSTALLATION [AJ].) (See THERMOSTAT INSPECTION.) • Is the thermostat normal?	Yes	Access ECT PID on the WDS or equivalent. Inspect both ECT PID and the temperature gauge on the instrument cluster readings. • If the temperature gauge on the instrument cluster indicates normal range but ECT PID is not the same as the temperature gauge reading, inspect the ECT sensor. • If the temperature gauge on the instrument cluster indicates cold range but ECT PID is normal, inspect the temperature gauge and heat gauge unit.
3		No	Replace thermostat.
4	• Verify test results. - If normal, 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 or reprogram the PCM.