No. 18 Cooling System Concerns-Runs Cold: Procedure

1. Is a customer complaint "Lack of passenger compartment heat" only?

   Result

   Result
   Yes
   No

Result:  2

Yes 

INSPECT THE A/C HEATER SYSTEM. 

1. Repair or replace the malfunctioning part according to the inspection results.

Result:  1

No 

See step  2

1. Does the engine speed continue at fast idle?

   Result

   Result
   Yes
   No

Result:  2

Yes 

PERFORM THE SYMPTOM TROUBLESHOOTING "NO. 9 FAST IDLE/RUNS ON". 

1. Refer to NO. 9 FAST IDLE/RUNS ON 

Result:  1

No 

See step  3

1. Access the Engine coolant temperature PID using the Techstream.

   Refer to ON-BOARD DIAGNOSTIC TEST

2. Compare the Engine coolant temperature PID and low engine coolant temperature indicator light and high engine coolant temperature warning light operation.
3. Is the Engine coolant temperature PID value same as indicator/warning light readings?

   Result

   Result
   Yes
   No

Result:  2

No 

INSPECT THE ECT SENSOR NO. 1. 

1. Refer to INSPECTION
2. If there is any malfunction:
   1. Replace the ECT sensor No. 1.

      Refer to REMOVAL

3. If there is no malfunction:
   1. Perform the combination meter symptom troubleshooting "LOW ENGINE COOLANT TEMPERATURE INDICATOR LIGHT/HIGH ENGINE COOLANT TEMPERATURE WARNING LIGHT ILLUMINATES OR FLASHES CONTINUOUSLY".

      Refer to LOW ENGINE COOLANT TEMPERATURE INDICATOR LIGHT/HIGH ENGINE COOLANT TEMPERATURE WARNING LIGHT ILLUMINATES OR FLASHES CONTINUOUSLY

Result:  1

Yes 

See step  4

1. Perform the Cooling Fan Control System Inspection.

   Refer to ON-VEHICLE INSPECTION

2. Does the cooling fan control system operate properly?

   Result

   Result
   Yes
   No

Result:  2

No 

REPAIR OR REPLACE THE MALFUNCTIONING PART ACCORDING TO THE INSPECTION RESULTS. 

Result:  1

Yes 

See step  5

1. Cool down the engine.
2. Remove the thermostat.

   Refer to REMOVAL

3. Inspect the thermostat operation.

   Refer to INSPECTION

4. Is there any malfunction?

   Result

   Result
   Yes
   No

Result:  1

No 

See step  7

Result:  2

Yes 

REPLACE THE THERMOSTAT. 

1. Refer to REMOVAL

1. Drain the engine coolant.

   Refer to REPLACEMENT

2. Has foreign matter penetrated the engine coolant?

   Result

   Result
   Yes
   No

Result:  1

No 

VERIFY THE TEST RESULTS. 

1. If normal, return to the diagnostic index to service any additional symptoms.

   Refer to PROBLEM SYMPTOMS TABLE

2. If the malfunction remains, inspect the related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis.
   1. If the vehicle is repaired, troubleshooting is completed.
   2. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the ECM if a later calibration is available. Retest.

Result:  2

Yes 

REPLACE THE ENGINE COOLANT. 

1. Refer to REPLACEMENT

1. Refer to INSTALLATION
2. Then go to the next step.

   Result

   Proceed to
   NEXT

Result:  1

NEXT 

See step  6