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.

NO COOL AIR (MANUAL A/C) (US) DIAGNOSTIC PROCEDURE

Step

Inspection

Action

VERIFY AIRFLOW CONDITION

Switch the ignition ON (engine off or on).
Set the airflow volume control dial to 1 or more.
Does air flow from the vent after operating the blower motor?

Yes

Go to the next step.

Go to Step 1 of the following troubleshooting.
(See INSUFFICIENT AIR (OR NO AIR) BLOWN FROM VENTS (MANUAL A/C) .)
(See AMOUNT OF AIR BLOWN FROM VENTS DOES NOT CHANGE (MANUAL A/C) (US) .)

INSPECT A/C COMPRESSOR OPERATION

Start engine.
Turn A/C switch on.
Does A/C compressor operate?

Yes

Go to Step 1 of the following troubleshooting.
(See AIR FROM VENTS NOT COLD ENOUGH (MANUAL A/C) .)

Go to the next step.

VERIFY DTCs FOR RELATED MODULES

Verify DTCs using the M-MDS.
- PCM (See DTC INSPECTION .)
- Dash-electrical supply unit (See DTC INSPECTION .)
- Body control module (BCM) (See DTC INSPECTION .)
Are any DTCs displayed?

Yes

Go to the applicable DTC inspection.

PCM (See DTC TABLE [PCM (SKYACTIV-G (US))] .)
Dash-electrical supply unit (See DTC TABLE [DASH-ELECTRICAL SUPPLY UNIT (US)] .)
Body control module (BCM) (See DTC TABLE [BODY CONTROL MODULE (BCM) (US)] .)

Go to the next step.

VERIFY MAGNETIC CLUTCH OPERATION

Access PCM PID A/C_SW using the M-MDS. (See PID/DATA MONITOR INSPECTION .)
Start engine.
Turn the PID A/C_SW to ON from OFF using the M-MDS simulation function. (See SIMULATION INSPECTION .)
Is the magnetic clutch engaged/disengaged according to the simulation function operation?

Yes

Go to the next step.

Go to Step 9.

VERIFY MEASURED VALUE OF A/C PRESSURE SENSOR

Access PCM PIDs AC_PRES_AFT_COMP and AC_PRES_BEF_EXP_VLV using the M-MDS. (See PID/DATA MONITOR INSPECTION .)
Monitor the AC_PRES_AFT_COMP and AC_PRES_BEF_EXP_VLV PIDs while turning on and off the air conditioner by switching the control panel.
Are PIDs normal?

Yes

Go to Step 7.

Go to the next step.

INSPECT REFRIGERANT PRESSURE SENSOR

Inspect the refrigerant pressure sensor. (See REFRIGERANT PRESSURE SENSOR INSPECTION (MANUAL A/C) (US) .)
Is the refrigerant pressure sensor normal?

Yes

Inspect the following and repair or replace if necessary.

Refrigerant charge amount (if refrigerant has discharged completely, replace receiver/drier (⁽¹⁾)) (See RECEIVER/DRIER REMOVAL/INSTALLATION [SKYACTIV-G] .)
A/C compressor (See A/C COMPRESSOR REMOVAL/INSTALLATION [SKYACTIV-G] .)

Perform the repair completion verification.

Replace refrigerant pressure sensor, then perform the repair completion verification.
(See REFRIGERANT PRESSURE SENSOR REMOVAL/INSTALLATION (MANUAL A/C) (US) .)

VERIFY MEASURED VALUE OF EVAPORATOR TEMPERATURE SENSOR

Access dash-electrical supply unit PID EVA_TMP using the M-MDS. (See PID/DATA MONITOR INSPECTION .)
Turn the climate control unit A/C switch on and off while the PID EVA_TMP is displayed.
Is the PID normal?

Yes

Perform the repair completion verification.

Go to the next step.

INSPECT EVAPORATOR TEMPERATURE SENSOR

Inspect the evaporator temperature sensor. (See EVAPORATOR TEMPERATURE SENSOR INSPECTION (MANUAL A/C) .)
Is the evaporator temperature sensor normal?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between evaporator temperature sensor terminal and climate control unit terminal.
If there is a common connector:

Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection.
Repair or replace the malfunctioning part.

If there is no common connector:

Repair or replace the wiring harness.

Perform the repair completion verification.

Replace the evaporator temperature sensor, then perform the repair completion verification.
(See EVAPORATOR TEMPERATURE SENSOR REMOVAL/INSTALLATION (MANUAL A/C) (US) .)

DETERMINE IF MALFUNCTION IS CAUSED BY A/C RELAY CIRCUIT MALFUNCTION OR PCM MALFUNCTION

Short circuit between A/C relay terminal E (A/C control signal) and ground.
Is there cool airflow?

Yes

Repair the short circuit and go to the next step.

Go to Step 13.

INSPECT A/C RELAY CONTROL CIRCUIT FOR OPEN CIRCUIT

Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION .)
Is the circuit normal?

Yes

Go to the next step.

Repair or replace the malfunctioning location and perform the repair completion verification.

INSPECT A/C RELAY CONTROL CIRCUIT FOR SHORT TO GROUND

Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
Is the circuit normal?

Yes

Go to the next step.

Repair or replace the malfunctioning location and perform the repair completion verification.

INSPECT MAGNETIC CLUTCH

Inspect the magnetic clutch. (See MAGNETIC CLUTCH INSPECTION [SKYACTIV-G] .)
Is the magnetic clutch normal?

Yes

Go to the next step.

Replace the magnetic clutch, then perform the repair completion verification.
(See MAGNETIC CLUTCH DISASSEMBLY/ASSEMBLY [SKYACTIV-G] .)

13*

INSPECT MAGNETIC CLUTCH POWER SUPPLY CIRCUIT FOR SHORT TO GROUND AND OPEN CIRCUIT

Inspect the power supply circuit for an open circuit and short to ground. (See CIRCUIT INSPECTION .)
Is the circuit normal?

Yes

Go to the next step.

Repair or replace the malfunctioning location and perform the repair completion verification.

14*

INSPECT A/C RELAY POWER SUPPLY CIRCUIT FOR OPEN CIRCUIT

Inspect the power supply circuit for an open circuit. (See CIRCUIT INSPECTION .)
Is the circuit normal?

Yes

Go to the next step.

Repair or replace the malfunctioning location and perform the repair completion verification.

15*

INSPECT A/C RELAY POWER SUPPLY CIRCUIT FOR SHORT TO GROUND

Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
Is the circuit normal?

Yes

Go to the next step.

Repair or replace the malfunctioning location and perform the repair completion verification.

16*

INSPECT MAGNETIC CLUTCH CONTROL CIRCUIT FOR OPEN CIRCUIT

Inspect the applicable circuit for open circuit. (See CIRCUIT INSPECTION .)
Is the circuit normal?

Yes

Go to the next step.

Repair or replace the malfunctioning location and perform the repair completion verification.

17*

INSPECT MAGNETIC CLUTCH CONTROL CIRCUIT FOR SHORT TO GROUND

Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .)
Is the circuit normal?

Yes

Replace the A/C relay and perform the repair completion verification.
(See RELAY LOCATION (US) .)

Repair or replace the malfunctioning location and perform the repair completion verification.

Repair completion verification

VERIFY THAT MALFUNCTION SYMPTOM DOES NOT RECUR AFTER REPAIR

Does cool air discharge from the vents? (Are the results of refrigerant system performance test normal?) (See REFRIGERANT SYSTEM PERFORMANCE TEST (US) .)

Yes

Troubleshooting completed. Explain repairs to customer.

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.

⁽¹⁾

If the refrigerant has completely leaked out, ambient air may penetrate the refrigerant system and the desiccant in the receiver/drier may absorb moisture in the ambient air resulting in saturation. If the refrigerant system is used under this condition, rust may generate in the A/C compressor due to the moisture, causing secondary problems such as A/C compressor lock or abnormal noise. Therefore, it will be necessary to replace the receiver/drier. (See RECEIVER/DRIER REMOVAL/INSTALLATION [SKYACTIV-G] .)