No. 17 Cooling System Concerns-Overheating

17	COOLING SYSTEM CONCERNS-OVERHEATING
DESCRIPTION	The engine runs at higher than normal temperature/overheats.
POSSIBLE CAUSE	Improper coolant level Blown fuses Coolant leakage A/C system operation is improper Improper water/anti-freeze mixture Fans reverse rotation Poor radiator condition Thermostat malfunction Radiator hoses damage Improper or damaged radiator cap Cooling fan is inoperative Coolant overflow system malfunction Improper tension of drive belt Drive belt damage

DIAGNOSTIC PROCEDURE

STEP	INSPECTION	RESULTS	ACTION
1	Inspect the following: Engine coolant level Coolant leakage Water and anti-freeze mixture Radiator condition Collapsed or restricted radiator hoses Radiator pressure cap Overflow system Fan rotational direction Fuses Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Turn the ignition switch to the ON position (Engine off). Retrieve any DTCs. Are there any DTCs displayed?	Yes	Go to the appropriate DTC inspection. (See DTC TABLE ).
2		No	Go to the next step.
3	Start the engine and idle it. Verify state of the A/C compressor while turing on and off the air conditioner by switching the control panel. Does the A/C compressor engage?	Yes	Go to Step 5.
3		No	If the A/C compressor is not engaged always. Go to the symptom troubleshooting "No. 23 A/C does not work sufficiently". (See NO. 23 A/C DOES NOT WORK SUFFICIENTLY ). If the A/C compressor is engaged always. Go to the symptom troubleshooting "No. 24 A/C is always on or A/C compressor runs continuously". (See NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY ).
4	Perform the Cooling Fan Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ). Does the cooling fan control system function properly?	Yes	Go to the next step.
4		No	Repair or replace the malfunctioning part according to the inspection results.
5	Is the drive belt normal?	Yes	Go to the next step.
5	Is the drive belt normal?	No	Replace the drive belt. (See DRIVE BELT REPLACEMENT ).
6	is there leakage around the heater unit in passenger compartment?	Yes	Inspect and service heater for leakage.
6		No	Go to the next step.
7	Is there leakage at the coolant hoses and/or radiator?	Yes	Repair or replace the malfunctioning part according to the inspection results.
7	Is there leakage at the coolant hoses and/or radiator?	No	Go to the next step.
8	Cool down the engine. Remove the thermostat and inspect the operation. (See THERMOSTAT REMOVAL/INSTALLATION ). (See THERMOSTAT INSPECTION ). Is the thermostat normal?	Yes	The engine coolant temperature and thermostat are normal, inspect engine block for leakage or blockage.
8		No	Access the ECT PID. Inspect for both ECT PID and temperature gauge readings. If the temperature gauge on instrument cluster indicates normal range but the ECT PID is not same as temperature gauge reading, inspect the ECT sensor. If temperature gauge on instrument cluster indicates overheating but the ECT PID is normal, inspect instrument cluster.
9	Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair 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 the PCM. (See PCM REMOVAL/INSTALLATION ).