Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

AIR FROM VENTS NOT COLD ENOUGH (MANUAL A/C) DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	INSPECT BLOWER UNIT AND AIR FILTER Are the blower unit intake and air filter clogged? (See AIR FILTER INSPECTION .)	Yes	Remove the cause of the blockage. Replace the air filter if it is clogged. (See AIR FILTER REMOVAL/INSTALLATION (US) .) After performing the repair, perform the repair completion verification.
1		No	Go to the next step.
2	INSPECT REFRIGERANT PRESSURE Inspect the refrigerant pressure. (See REFRIGERANT PRESSURE CHECK (US) .) Is the refrigerant pressure normal?	Yes	Go to the next step.
2		No	Record the inspection results. If the refrigerant pressures on the high pressure and low pressure side are both high, go to Step 6. If the refrigerant pressures on the high pressure and low pressure sides are almost same, go to Step 9. If the refrigerant pressures on the high pressure and low pressure sides are both low, go to Step 11. If vacuum on the low pressure side and the refrigerant pressure on the high pressure side is extremely low, go to Step 12. If the refrigerant pressure on the high pressure side is low and the refrigerant pressure on the low pressure side is high, replace the A/C compressor, then perform the repair completion verification. (See A/C COMPRESSOR REMOVAL/INSTALLATION [SKYACTIV-G] .) If the refrigerant pressure condition is under any condition other than the above, go to Step 14.
3	PERFORM AIR-CONDITIONING SYSTEM PERFORMANCE TEST Perform the air-conditioning system performance test. (See REFRIGERANT SYSTEM PERFORMANCE TEST (US) .) Is the airflow temperature within the specified range?	Yes	Perform the repair completion verification.
3		No	Go to the next step.
4	INSPECT DRIVE BELT Inspect the drive belt. (See DRIVE BELT INSPECTION [SKYACTIV-G (VIN L (US))] .) (See DRIVE BELT INSPECTION [SKYACTIV-G (VIN M (US))] .) Is the drive belt condition normal?	Yes	Go to the next step.
4		No	After adjusting the drive belt tension, go to the next step. (See DRIVE BELT REMOVAL/INSTALLATION [SKYACTIV-G (VIN L (US))] .) (See DRIVE BELT REMOVAL/INSTALLATION [SKYACTIV-G (VIN M (US))] .)
5	INSPECT A/C PRESSURE SENSOR Inspect the A/C pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION (MANUAL A/C) (US) .) Is the A/C pressure sensor normal?	Yes	Go to the next step.
5		No	Replace the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION (MANUAL A/C) (US) .) After performing the repair, perform the repair completion verification.
6	INSPECT COOLING FAN Verify the cooling fan operation. (See COOLING FAN MOTOR INSPECTION [SKYACTIV-G (VIN L (US))] .) (See COOLING FAN MOTOR INSPECTION [SKYACTIV-G (VIN M (US))] .) Is the cooling fan operation normal?	Yes	Go to the next step.
6		No	Repair or replace the malfunctioning location according to the inspection results. After performing the repair, perform the repair completion verification.
7	INSPECT CONDENSER Inspect the condenser. (See CONDENSER INSPECTION [SKYACTIV-G] .) Is it normal?	Yes	Go to the next step.
7		No	Repair or replace the malfunctioning location according to the inspection results. (See CONDENSER REMOVAL/INSTALLATION [SKYACTIV-G] .) After performing the repair, perform the repair completion verification.
8	INSPECT SYSTEM PIPING Is the hose on the low pressure side hot to the touch?	Yes	Replace the refrigerant. After vacuum discharging for 1 h and charging with refrigerant to the specified level, perform the repair completion verification. (See REFRIGERANT CHARGING (US) .)
8		No	Replace the refrigerant. After vacuum discharging for 15 min and charging with refrigerant to the specified level, perform the repair completion verification. (See REFRIGERANT CHARGING (US) .)
9	INSPECT EXPANSION VALVE Remove the expansion valve and verify its condition. (See EXPANSION VALVE REMOVAL/INSTALLATION (US) .) Is there refrigerant leakage or valve blockage?	Yes	If there is foreign matter blockage the valve, remove the foreign matter. If there is refrigerant leakage or blockage, replace the expansion valve. (See EXPANSION VALVE REMOVAL/INSTALLATION (US) .) Perform the repair completion verification.
9		No	Go to the next step.
10	DETERMINE IF MALFUNCTION CAUSE IS A/C COMPRESSOR OR AIR MIX ACTUATOR Start the engine and idle it. Access the following dash-electrical supply unit PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION .) AIR MIX_L Are PID values normal?	Yes	After adjusting the compressor oil to the specified level, perform the repair completion verification. (See A/C COMPRESSOR REMOVAL/INSTALLATION [SKYACTIV-G] .)
10		No	Verify the air mix link and air mix door installation conditions. (See A/C UNIT DISASSEMBLY/ASSEMBLY (US) .) Securely and correctly installed to positions Replace the air mix actuator. (See AIR MIX MAIN LINK REMOVAL/INSTALLATION .) Not securely and correctly installed to positions Repair the air mix link and air mix door installation conditions. (See A/C UNIT DISASSEMBLY/ASSEMBLY (US) .) Perform the repair completion verification.
11	INSPECT SYSTEM PIPING Verify if there is gas leakage from the system piping using the gas leak tester. Is the system piping normal?	Yes	Replace the crushed system piping or the malfunctioning location. (See REFRIGERANT LINE REMOVAL/INSTALLATION [SKYACTIV-G] .) Perform the repair completion verification.
11		No	Replace the O-ring of the malfunctioning location (system piping connecting area). Or replace the malfunctioning location of the system piping. (See REFRIGERANT LINE REMOVAL/INSTALLATION [SKYACTIV-G] .) Perform the repair completion verification.
12	INSPECT REFRIGERANT PRESSURE Does the refrigerant pressure on the low pressure side vary between the vacuum and normal range?	Yes	Replace the condenser (moisture has penetrated engine coolant). (See CONDENSER REMOVAL/INSTALLATION [SKYACTIV-G] .) Perform the repair completion verification.
12		No	Go to the next step.
13	INSPECT EXPANSION VALVE Remove the expansion valve and verify its condition. (See EXPANSION VALVE REMOVAL/INSTALLATION (US) .) Is there refrigerant leakage or valve blockage?	Yes	If there is foreign matter blockage the valve, remove the foreign matter. If there is refrigerant leakage or blockage, replace the expansion valve. (See EXPANSION VALVE REMOVAL/INSTALLATION (US) .) Perform the repair completion verification.
13		No	Install the expansion valve, then perform the repair completion verification.
14	INSPECT EVAPORATOR TEMPERATURE SENSOR Inspect the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION (MANUAL A/C) .) Is the evaporative temperature sensor normal?	Yes	Verify the evaporator temperature installation condition and repair the installation position. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION (MANUAL A/C) (US) .) Go to the next step.
14		No	Replace the evaporative temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION (MANUAL A/C) (US) .) After replacement, perform the repair completion verification.
15	DETERMINE IF MALFUNCTION CAUSE IS A/C COMPRESSOR OR AIR MIX ACTUATOR Start the engine and idle it. Access the following dash-electrical supply unit PIDs using the M-MDS: (See PID/DATA MONITOR INSPECTION) . AIR MIX_L Are PID values normal?	Yes	Perform the repair completion verification.
15		No	Verify the air mix link and air mix door installation conditions. (See A/C UNIT DISASSEMBLY/ASSEMBLY (US) .) Securely and correctly installed to positions Replace the air mix actuator. (See AIR MIX ACTUATOR REMOVAL (MANUAL A/C) (US) .) (See AIR MIX ACTUATOR INSTALLATION (MANUAL A/C) (US) .) Not securely and correctly installed to positions Repair the air mix link and air mix door installation conditions. (See A/C UNIT DISASSEMBLY/ASSEMBLY (US) .) Perform the repair completion verification.
Repair completion verification	VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR If refrigerant was discharged during inspection and not recharged, perform vacuum discharging and charge with new refrigerant to the specified level. (See REFRIGERANT CHARGING (US) .) Is there cool airflow (is the result of refrigerant system performance test normal?)? (See REFRIGERANT SYSTEM PERFORMANCE TEST (US) .)	Yes	Troubleshooting completed. Explain repairs to customer.
Repair completion verification		No	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW (US) .) If the CAN communication is normal, perform the diagnosis from Step 1.