NO.22 COOLING SYSTEM CONCERNS-OVERHEATING [SKYACTIV-D 2.2]


id0103g1898900

22

COOLING SYSTEM CONCERNS-OVERHEATING

DESCRIPTION
•  The engine coolant temperature is abnormally high.
POSSIBLE CAUSE
•  PCM DTC is stored.
•  Erratic signal to PCM
―  ECT sensor or related circuit malfunction
•  A/C relay malfunction
•  Fan control module No.1 malfunction
•  Fan control module No.2 malfunction
•  Cooling system malfunction
―  Cooling fan motor malfunction
―  Thermostat malfunction
―  Engine coolant passage (including radiator) malfunction (clogging, leakage)


Diagnostic Procedure

STEP

INSPECTION

RESULTS

ACTION

1
VERIFY PCM DTC
•  Retrieve PCM DTCs using the M-MDS.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
No
Go to the next step.
2
VERIFY CURRENT INPUT SIGNAL STATUS
Caution
•  While performing this step, always operate the vehicle in a safe and lawful manner.
•  When the M-MDS is used to observe monitor system status while driving, be sure to have another technician with you, or record the data in the M-MDS using the PID/DATA MONITOR AND RECORD capturing function and inspect later.
•  Access the following PID using the M-MDS:
―  ECT
•  Does the PID indicate the correct value under the trouble condition?
Yes
Inspect the related sensor and circuit.
•  If there is any malfunction:
―  Repair or replace the malfunctioning part according to the inspection results, then go to Step 11.
•  If there is no malfunction:
―  Go to the next step.
No
Go to the next step.
3
INSPECT A/C RELAY
•  Switch the ignition off.
•  Remove the A/C relay.
•  Inspect the A/C relay.
•  Is the A/C relay normal?
Yes
Go to the next step.
No
Replace the A/C relay, then go to Step 11.
4
INSPECT FAN CONTROL MODULE NO.1
•  Inspect the fan control module No.1.
•  Is the fan control module No.1 normal?
Yes
Go to the next step.
No
Replace the fan control module No.1, then go to Step 11.
5
INSPECT FAN CONTROL MODULE NO.2
•  Inspect the fan control module No.2.
•  Is the fan control module No.2 normal?
Yes
Go to the next step.
No
Replace the fan control module No.2, then go to Step 11.
6
INSPECT COOLING FAN MOTOR NO.1
•  Inspect the cooling fan motor No.1.
•  Is the cooling fan motor No.1 normal?
Yes
Go to the next step.
No
Replace the cooling fan motor No.1, then go to Step 11.
7
INSPECT COOLING FAN MOTOR NO.2
•  Inspect the cooling fan motor No.2.
•  Is the cooling fan motor No.2 normal?
Yes
Go to the next step.
No
Replace the cooling fan motor No.2, then go to Step 11.
8
DETERMINE IF MALFUNCTION CAUSE IS THERMOSTAT OR OTHER
•  Verify the radiator hose tension.
Warning
•  To prevent burns, use a cloth with your hand to verify the tension of the radiator hose.
•  After the engine warms up, does the engine coolant circulate to the radiator hose?
Yes
Go to Step 10.
No
Go to the next step.
9
INSPECT THERMOSTAT
•  Inspect the thermostat.
•  Is the thermostat normal?
Yes
Go to the next step.
No
Replace the thermostat, then go to Step 11.
10
INSPECT SEALING OF ENGINE
•  Verify that there is no engine coolant leakage.
•  Is the sealing of engine normal?
Yes
Inspect for clogging in the engine coolant passage.
•  If there is any malfunction:
―  Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
•  If there is no malfunction:
―  Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
11
Verify the test results.
•  If normal, return to the diagnostic index to service any additional symptoms.
•  If a malfunction remains, inspect the related Service Information and perform the repair or diagnosis.
―  If the vehicle is repaired, troubleshooting is completed.
―  If the vehicle is not repaired or additional diagnostic information is not available, replace the PCM.