NO.17 COOLING SYSTEM CONCERNS-OVERHEATING [WL-C, WE-C]

id0103b6802300

17

COOLING SYSTEM CONCERNS-OVERHEATING

DESCRIPTION

•  Engine runs at higher than normal temperature/overheats.

POSSIBLE CAUSE

•  Cooling fan malfunction

•  Low drive belt tension

•  Drive belt damage

•  Improper coolant level

•  Thermostat malfunction

•  Radiator clogging

•  Improper water/anti-freeze mixture

•  Improper or damaged radiator cap

•  Radiator hose damage

•  Coolant leakage (engine internal, turbocharger, external)

•  A/C system malfunction

•  EGR system malfunction

•  Coolant heater system malfunction

17	COOLING SYSTEM CONCERNS-OVERHEATING
DESCRIPTION	• Engine runs at higher than normal temperature/overheats.
POSSIBLE CAUSE	• Cooling fan malfunction • Low drive belt tension • Drive belt damage • Improper coolant level • Thermostat malfunction • Radiator clogging • Improper water/anti-freeze mixture • Improper or damaged radiator cap • Radiator hose damage • Coolant leakage (engine internal, turbocharger, external) • A/C system malfunction • EGR system malfunction • Coolant heater system malfunction

Diagnostic Procedure

STEP	INSPECTION	RESULTS	ACTION
1	Inspect the following: • Engine coolant level • Coolant leakage (around heater unit in passenger compartment, coolant hoses and/or radiator, and around coolant heater unit.) • Water and anti-freeze mixture • Radiator condition • Collapsed or restricted radiator hoses • Radiator pressure cap • Drive belt tension • Drive belt • Fan rotational direction Are all items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1.
2	Perform the self-test function using the M-MDS. Turn the engine switch to the ON position (Engine off). Retrieve any DTCs. Are any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC test. (See DTC TABLE [WL-C, WE-C (Thailand, General (L.H.D. R.H.D.) specs.)].) Communication error message is displayed: Inspect the following: • Open circuit between main relay and PCM terminal 201, 203, 205 • Open circuit main relay and PCM terminal 219 • Main relay stuck open • Open or poor ground circuit (PCM terminal 202, 204, 206) • Poor connection to vehicle body ground
2		No	No DTC is displayed: Go to the next step.
3	Note • The following test should be performed on the vehicles with an A/C system. Go to the next step for vehicles without an A/C system Start the engine and run it at idle speed. Turn the A/C switch off. Does the A/C compressor disengage?	Yes	Go to the next step.
3		No	Go to the symptom troubleshooting “NO.24 A/C ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [WL-C, WE-C]”.
4	Is the drive belt normal?	Yes	Go to the next step.
4	Is the drive belt normal?	No	Replace the drive belt.
5	Is there any leakage around heater unit in passenger compartment?	Yes	Inspect and service heater for leakage.
5		No	Go to the next step.
6	Is there any leakage at coolant hoses and/or radiator?	Yes	Replace malfunction parts.
6	Is there any leakage at coolant hoses and/or radiator?	No	Go to the next step.
7	Perform the EGR system inspection. Is the EGR system normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning part according to the EGR system operation results.
8	Perform the coolant heater system inspection. (See THERMOSTAT INSPECTION [WL-C, WE-C].) Is the coolant heater system normal?	Yes	Go to the next step.
8		No	Repair or replace the malfunctioning part according to the coolant heater system operation results.
9	Cool down engine. Remove the thermostat and inspect the operation. Is the thermostat normal?	Yes	Thermostat is normal. Inspect the cylinder block for leakage or blockage.
9		No	Replace thermostat.
10	Verify test results. • If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [WL-C, WE-C].) • If the malfunction remains, inspect the related Service Information and perform repair or diagnosis. ― If the vehicle is repaired, troubleshooting completed. ― If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if later calibration is available. Retest.