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

BME010300000W12

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

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 normal?
Yes
Go to next step.
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.
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.
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.
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.
No | Replace drive belt.
6 | • Is there any leakage around heater unit in passenger compartment? | Yes | Inspect and service heater for leakage.
No | Go to next step.
7 | • Is there any leakage at coolant hoses and/or radiator? | Yes | Replace malfunctioning part.
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.
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.