NO.16 COOLING SYSTEM CONCERNS-OVERHEATING [F2]

id010394850900

16

COOLING SYSTEM CONCERNS -OVERHEATING

DESCRIPTION

Engine runs at higher than normal temperature/overheats.

POSSIBLE CAUSE

•  Improper coolant level

•  Blown fuses

•  Coolant leakage/Improper coolant level

•  Excessive A/C system pressure

•  Improper water/anti‐freeze mixture

•  Fans reverse rotation

•  Poor radiator condition

•  Thermostat malfunction

•  Radiator hose damage

•  Improper or damaged radiator cap

•  Main cooling fan is inoperative.

•  Coolant overflow system malfunction

•  Improper tension of drive belt

•  Drive belt damage

16	COOLING SYSTEM CONCERNS -OVERHEATING
DESCRIPTION	Engine runs at higher than normal temperature/overheats.
POSSIBLE CAUSE	• Improper coolant level • Blown fuses • Coolant leakage/Improper coolant level • Excessive A/C system pressure • Improper water/anti‐freeze mixture • Fans reverse rotation • Poor radiator condition • Thermostat malfunction • Radiator hose damage • Improper or damaged radiator cap • Main 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	Connect the M-MDS to the DLC-2. Turn ignition switch on. Retrieve any DTC. Is “NO CODES RECEIVED” or “SYSTEM PASSED” displayed?	Yes	No DTC is displayed: Go to the next step.
2		No	DTC is displayed: Go to the appropriate DTC inspection. (See DTC TABLE [F2].)
3	Start the engine and idle it. Turn the A/C switch on. Does A/C compressor engage?	Yes	Go to Step 5.
3		No	Inspect for the following and repair or replace if necessary: • Refrigerant charging amount • Open circuit in wiring harness between A/C relay and PCM terminal 1J • Seized A/C magnetic clutch • A/C magnetic clutch malfunction If all items are normal, go to the next step.
4	Connect the M-MDS to the DLC-2. Access ACSW PID on M-MDS. Start the engine and idle it. Turn the A/C switch on. Does ACSW PID read ON?	Yes	Go to the next step.
4		No	Inspect the following: • Refrigerant pressure switch operation • A/C switch is stuck open. • Open or short circuit between refrigerant pressure switch and PCM terminal 1Q • Open circuit of blower motor fan switch and resistor (if blower motor does not operate) • Evaporator temperature sensor and A/C amplifier
5	Is the drive belt normal?	Yes	Go to the next step.
5	Is the drive belt normal?	No	Replace the drive belt. (See TIMING BELT REMOVAL/INSTALLATION [F2].)
6	Is there leakage around heater unit in passenger compartment?	Yes	Inspect and service heater for leakage.
6		No	Go to the next step.
7	Is there leakage at coolant hoses and/or radiator?	Yes	Replace the malfunctioning part.
7	Is there leakage at coolant hoses and/or radiator?	No	Go to the next step.
8	Cool down the engine. Remove the thermostat and inspect operation. (See THERMOSTAT INSPECTION [F2].) Is the thermostat normal?	Yes	Engine coolant temperature sensor and the thermostat are normal, inspect the engine block for leakage or blockage.
8		No	Access ECT PID. Inspect for both ECT PID and the temperature gauge readings. • If the temperature gauge on the instrument cluster indicates normal range but ECT PID is not same as the temperature gauge reading, inspect the ECT sensor. • If the temperature gauge on the instrument cluster indicates overheating but ECT PID is normal, inspect the temperature gauge and the heat gauge unit.
9	• Verify test results. ― If normal, return to diagnostic index to service any additional symptoms. (See ENGINE SYMPTOM TROUBLESHOOTING [F2].) ― 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 the PCM. (See PCM REMOVAL/INSTALLATION [F2].)