LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2014 >> CX-5 Sport, 4D Utility, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting - Engine Controls >> No. 17 Cooling System Concerns-Overheating >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

DIAGNOSTIC PROCEDURE

STEP INSPECTION RESULTS ACTION
1 INSPECT VEHICLE CONDITION FOR EFFECT ON MALFUNCTION 
  • Verify how the customer drives the vehicle by asking the customer the following:
    • Engine speed is high and remains high for continuous long periods like when climbing a long, steep grade.
  • Is the engine generating excessive heat when driven?
Yes Explain to the customer that the vehicle is normal and give them advice how to use vehicle and provide a specific example of the conditions in which the engine overheats.
No Go to the next step.
2 DETERMINE IF MALFUNCTION CAUSE IS A/C SYSTEM OR OTHER 
  • Start the engine and run it at idle speed.
  • Turn the A/C switch off.
  • Does the A/C compressor disengaged?
Yes Go to the next step.
No Perform the symptom troubleshooting "NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY".
(See NO. 24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY .)
3 VERIFY PCM DTC 
Yes Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)
No Go to the next step.
4 INSPECT ECT SENSOR NO. 1 SIGNAL 
  • Access the ECT PID using the M-MDS.

    (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .)

  • Compare the ECT PID and low engine coolant temperature indicator light and high engine coolant temperature warning light operation.
  • Is the ECT PID value same as indicator/warning light readings?
Yes Go to the next step.
No Inspect the ECT sensor No. 1.
(See ENGINE COOLANT TEMPERATURE (ECT) SENSOR INSPECTION .)
5 INSPECT COOLING FAN CONTROL SYSTEM OPERATION 
Yes Go to the next step.
No Repair or replace the malfunctioning part according to the inspection results.
6 INSPECT RELATED PART CONDITION 
  • Inspect the following:
    • Engine coolant level
    • Engine coolant performance
    • Water and anti-freeze mixture
    • Radiator condition
    • Collapsed or restricted radiator hoses
    • Radiator pressure cap
    • Coolant overflow system
    • Fan rotational direction
    • Fuses
  • Is there any malfunction?
Yes Service if necessary.
  • Repeat this step.
No Go to the next step.
7 INSPECT COOLANT LEAKAGE AT COOLING SYSTEM PART 
  • Inspect for leakage at coolant hoses and/or radiator.
  • Is there any leakage?
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
8 INSPECT COOLANT LEAKAGE AT HEATER UNIT 
  • Inspect for leakage around heater unit in passenger compartment.
  • Is there any leakage?
Yes Repair or replace the malfunctioning part according to the inspection results.
No Go to the next step.
9 INSPECT DRIVE BELT 
Yes Replace the drive belt.
(See DRIVE BELT REMOVAL/INSTALLATION .)
No Go to the next step.
10 INSPECT THERMOSTAT 
Yes Replace the thermostat.
(See THERMOSTAT REMOVAL/INSTALLATION .)
No Reinstall the thermostat.
(See THERMOSTAT REMOVAL/INSTALLATION .) The engine coolant temperature and thermostat are normal.
  • Inspect the engine block for leakage or blockage.
  • Repair or replace the malfunctioning part according to the inspection results.
11 Verify the test results.
  • If normal, return to the diagnostic index to service any additional symptoms.

    (See SYMPTOM DIAGNOSTIC INDEX .)

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