NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [AJ] (VIN: JM0 LW10J300 301406-, JMZ LW69J7*# 307683-, JM8 LW28J**# 301514-, JM8 LW28A**# 301514- (Assumed))


17	Cooling system concerns-overheating
DESCRIPTION	• Engine runs at higher than normal temperature/overheats.
POSSIBLE CAUSE	• Improper coolant level • Blown fuses • Coolant leakage • Excessive A/C system pressure • Improper water/anti-freeze mixture • Fans reverse rotation • Poor radiator condition • Thermostat malfunction • Radiator hoses damage • Condenser fan is inoperative. • Improper or damaged radiator cap • Cooling fan is inoperative. • Coolant overflow system malfunction • Improper tension of drive belt • Drive belt damage • Fan control module malfunction


STEP	INSPECTION		ACTION
1	• Inspect 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 next step.
1		No	Service as necessary. Repeat Step 1.
2	• Connect WDS or equivalent to DLC-2. • Turn ignition switch to ON (Engine OFF). • Retrieve any DTCs. • Is "PASSED" displayed?	Yes	No DTC is displayed: • Go to next step.
2		No	DTC is displayed: • Go to appropriate DTC test.
3	• Start engine and run it at idle speed. • Turn A/C switch on. • Does A/C compressor engage?	Yes	Go to step 5.
3		No	Inspect following and repair or replace as necessary: • Refrigerant charging amount • Open circuit between A/C relay and PCM terminal 47 • Seized A/C magnetic clutch • A/C magnetic clutch malfunction - If all items are normal, Inspect following: • Refrigerant pressure switch operation • Evaporator temperature sensor and A/C amplifier • A/C switch is stuck open. • Open or short circuit between refrigerant pressure switch and PCM terminal 5 • Open circuit of blower motor fan switch and resistor (if blower motor does not operate)
4	• Start engine and run it at idle speed. • Turn A/C switch ON. • Do cooling fan and condenser fan operate?	Yes	Go to next step.
4		No	Cooling fan motor does not operate: • Inspect for following: - Cooling fan motor malfunction - Cooling fan motor GND open - Open circuit between cooling fan motor and fan control module Condenser fan motor does not operate: • Inspect for following: - Condenser fan motor malfunction - Condenser fan motor GND open - Open circuit between condenser fan motor and fan control module Both cooling fan and condenser fan do not operate: • Inspect for following: - Fan control module malfunction - Fan control module GND open - Open circuit between fan control module and cooling fan relay
5	• Is drive belt normal?	Yes	Go to next step.
5	• Is drive belt normal?	No	Replace drive belt.
6	• Is there any leakage around heater unit in passenger compartment?	Yes	Inspect and service heater for leakage.
6		No	Go to next step.
7	• Is there any leakage at coolant hoses and/or radiator?	Yes	Replace malfunctioning part.
7	• Is there any leakage at coolant hoses and/or radiator?	No	Go to next step.
8	• Cool down engine. • Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION [AJ].) (See THERMOSTAT INSPECTION.) • Is thermostat normal?	Yes	Engine coolant temperature and thermostat are normal. Inspect engine block for leakage or blockage.
8		No	Access ECT PID on WDS or equivalent. Inspect both ECT PID and temperature gauge 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 overheating but ECT PID is normal, inspect temperature gauge and heat gauge unit.
9	• 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 PCM.