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

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

id0103a4802400

18

COOLING SYSTEM CONCERNS-RUNS COLD

DESCRIPTION

Engine takes excessive time to reach normal operating temperature.

POSSIBLE CAUSE

• Thermostat malfunction

• Cooling fan system malfunction

Diagnostic procedure

STEP	INSPECTION	RESULTS	ACTION
1	Is customer complaint "Lack of passenger compartment heat" only?	Yes	Inspect A/C and heater system.
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[L3].)
2	Does the engine speed continue at fast idle?	No	Go to the next step.
3	Remove the thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION[L3].) (See THERMOSTAT INSPECTION[L3].) Is thermostat normal?	Yes	Go to the next step.
3		No	Replace the thermostat.
4	Inspect cooling fan control system operation. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION[L3].) Does the cooling fan control system function properly?	Yes	Access ECT PID. Inspect for both ECT PID and temperature gauge on instrument cluster readings. • If the temperature gauge on the instrument cluster indicates normal range but ECT PID is not the same as 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.
4		No	Repair or replace the malfunctioning part.
5	• Verify test results. ― If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING[L3].) ― 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. (See PCM REMOVAL/INSTALLATION[L3].)