Diagnostic Procedure

NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [BP, BP WITH TC] DIAGNOSTIC PROCEDURE

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 okay?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Connect WDS or equivalent to DLC-2. Turn ignition switch to ON. Retrieve any DTC. Is "PASSED" displayed?	Yes	No DTC displayed: Go to the next step.
2		No	DTC 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 4.
3		No	Inspect following and repair or replace if necessary: Refrigerant charging amount Open circuit between A/C magnetic clutch relay and PCM terminal 2K Seized A/C magnetic clutch A/C magnetic clutch malfunction If all items are okay, inspect for following: A/C pressure switch operation A/C switch is stuck open Open or short circuit between A/C pressure switch and PCM terminal 4F Open circuit of blower motor fan switch and resistor (if blower motor does not operate) Evaporator temperature sensor and amplifier
4	Start engine and run it at idle speed. Turn A/C switch on. Do condenser fan and main cooling fan operate?	Yes	Go to the next step.
4		No	If condenser fan does not operate, inspect for following: Condenser fan relay is stuck open. Condenser fan motor malfunction Condenser fan motor GND open Open circuit between condenser fan motor and relay Open circuit between condenser fan relay and PCM terminal 2C Open battery power circuit for condenser fan relay If main cooling fan motor does not operate, inspect for following: Main cooling fan relay is stuck open. Main cooling fan motor malfunction Main cooling fan motor GND open Open circuit between cooling fan motor and relay Open circuit between cooling fan relay and PCM terminal 2B Open battery power circuit for cooing fan relay
5	Is drive belt okay?	Yes	Go to the next step.
5	Is drive belt okay?	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 the next step.
7	Is there any leakage in coolant hoses and/or radiator?	Yes	Replace malfunctioning parts.
7	Is there any leakage in coolant hoses and/or radiator?	No	Go to the next step.
8	Cool down the engine. Remove thermostat and inspect operation. (See THERMOSTAT REMOVAL/INSTALLATION ) (See THERMOSTAT INSPECTION ) Is thermostat okay?	Yes	ECT and thermostat are okay, inspect engine block for leakage or blockage.
8		No	Access ECT PID on WDS or equivalent. Inspect for both ECT and temperature gauge readings. If temperature gauge on instrument cluster indicates normal range but ECT is not same as temperature gauge reading, inspect ECT sensor. If temperature gauge on instrument cluster indicates overheating but ECT is normal, inspect temperature gauge and heat gauge unit.
9	Verify test results. If okay, return to diagnostic index to service any additional symptoms. 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 PCM.