Diagnostic procedure

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

STEP	INSPECTION	RESULTS	ACTION
1	Inspect the 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 the items normal?	Yes	Go to the next step.
1		No	Service if necessary. Repeat Step 1
2	Connect the M-MDS to the DLC-2. Switch the ignition to ON (Engine off) Retrieve any DTCs Are there any DTCs displayed?	Yes	DTC is displayed: Go to the appropriate DTC inspection (See DTC TABLE [L5] .)
2		No	No DTC is displayed: Go to the next step.
3	Start the engine and idle it Turn the A/C switch on and set the blower fan to any speed. Does the A/C compressor engage?	Yes	Go to Step 5
3		No	Inspect for the following and repair or replace if necessary Refrigerant charging amount Open circuit in the wiring harness between the A/C relay and PCM terminal 1I Seized A/C magnetic clutch A/C magnetic clutch malfunction If all items are normal, go to the next step
4	Start the engine and idle it Turn the A/C switch on and set the blower fan to any speed Measure the voltage at PCM terminal 1J. (See PCM INSPECTION [L5] .) Is the voltage normal?	Yes	Go to the next step
4		No	Inspect the following Refrigerant pressure sensor operation The A/C switch is stuck open Open or short circuit between the refrigerant pressure sensor and PCM terminal 1J Open circuit in the blower motor fan switch and the resistor (if blower motor does not operate) The evaporator temperature sensor and climate control unit
5	Inspect the cooling fan control system operation (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [L5] ) Does the cooling fan control system function properly?	Yes	Go to the next step
5		No	Repair or replace the malfunctioning part
6	Is the drive belt normal? (See DRIVE BELT INSPECTION [L5] .)	Yes	Go to the next step
6		No	Replace the drive belt (See DRIVE BELT REMOVAL/INSTALLATION [L5] .)
7	Is there leakage around the heater unit in the passenger compartment?	Yes	Inspect and service heater for leakage
7		No	Go to the next step.
8	Is there leakage at the coolant hoses and/or radiator?	Yes	Replace the malfunctioning part
8	Is there leakage at the coolant hoses and/or radiator?	No	Go to the next step
9	Cool down the engine Remove thermostat and inspect operation (See THERMOSTAT REMOVAL/INSTALLATION [L5] .) (See THERMOSTAT INSPECTION [L5] .) Is the thermostat normal?	Yes	The engine coolant temperature and thermostat are normal, inspect engine block for leakage or blockage
9		No	Access ECT PID Inspect both the ECT PID and temperature gauge readings If the temperature gauge on instrument cluster indicates a normal range but the ECT PID is not the same as the temperature gauge reading, inspect the ECT sensor If the temperature gauge on the instrument cluster indicates overheating but the ECT PID is normal, inspect the temperature gauge and the heat gauge unit
10	Verify the test results If normal, return to the diagnostic index to service any additional symptoms (See SYMPTOM DIAGNOSTIC INDEX [L5] ) 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.