Diagnostic Procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

DUAL A/C CONTROL DOES NOT OPERATE (FULL-AUTO AIR CONDITIONER) - DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	VERIFY SYMPTOM Turn on the A/C. Perform the dual A/C control function for driver and passenger side individually. Is it either the temperature control on driver side or passenger side?	Yes	Go to the next step.
1		No	Go to Step 12.
2	INSPECT TO SEE WHETHER MALFUNCTION IS IN AIR MIX DOOR OR ELSEWHERE Turn on the A/C. Change temperature control on the suspected side while in dual mode. Does the air mix door on the suspect side move smoothly?	Yes	Go to Step 8.
2		No	Go to the next step.
3	INSPECT AIR MIX ACTUATOR Inspect the air mix actuator on the suspect side. (See AIR MIX ACTUATOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) Is the air mix actuator normal?	Yes	Go to the next step.
3		No	Replace the air mix actuator on the suspected side, then go to Step 15. (See AIR MIX ACTUATOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
4*	INSPECT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO GROUND Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Inspect for continuity between the following terminals (wiring harness-side) and body ground: Driver-side Climate control unit terminal 2D Climate control unit terminal 2B Passenger-side Climate control unit terminal 2H Climate control unit terminal 2F Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for a short to ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Go to Step 15.
4*		No	Go to the next step.
5*	INSPECT AIR MIX ACTUATOR CIRCUIT FOR OPEN CIRCUIT Air mix actuator and climate control unit connectors are disconnected. Inspect for continuity between the following terminals (wiring harness-side): Driver-side Climate control unit terminal 2D-air mix actuator terminal B Climate control unit terminal 2B-air mix actuator terminal C Passenger-side Climate control unit terminal 2H-air mix actuator terminal B Climate control unit terminal 2F-air mix actuator terminal C Is there continuity?	Yes	Go to the next step.
5*		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 15.
6*	INSPECT AIR MIX ACTUATOR CIRCUIT FOR SHORT TO POWER SUPPLY Air mix actuator and climate control unit connectors are disconnected. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Switch the ignition ON (engine off or on). Measure the voltage at the following terminals (wiring harness-side): Driver-side Climate control unit terminal 2D Climate control unit terminal 2B Passenger-side Climate control unit terminal 2H Climate control unit terminal 2F Is the voltage 0 V?	Yes	Go to the next step.
6*		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for a short to power supply. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to power supply. Go to Step 15.
7	INSPECT AIR MIX DOOR Inspect the suspect side air mix door. Is the air mix door normal?	Yes	Replace the climate control unit, then go to Step 15. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
7		No	Remove the obstruction or replace A/C unit case on the suspected side, then go to Step 15. (See A/C UNIT REMOVAL/INSTALLATION .)
8*	INSPECT AIR MIX ACTUATOR POSITION SENSOR Inspect the air mix actuator position sensor on the suspected side. (See AIR MIX ACTUATOR INSPECTION [FULL-AUTO AIR CONDITIONER] .) Is the air mix actuator position sensor normal?	Yes	Go to the next step.
8*		No	Replace the air mix actuator on the suspected side, then go to Step 15. (See AIR MIX ACTUATOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
9*	INSPECT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Inspect for continuity between the following terminals (wiring harness-side) and body ground: Driver-side Climate control unit terminal 2G Passenger-side Climate control unit terminal 2E Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for a short to ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Go to Step 15.
9*		No	Go to the next step.
10*	INSPECT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT Air mix actuator and climate control unit connectors are disconnected. Inspect for continuity between the following terminals (wiring harness-side): Driver-side Climate control unit terminal 2G-air mix actuator terminal F Climate control unit terminal 1N-air mix actuator terminal G Climate control unit terminal 1J-air mix actuator terminal E Passenger-side Climate control unit terminal 2E-air mix actuator terminal F Climate control unit terminal 1N-air mix actuator terminal E Climate control unit terminal 1J-air mix actuator terminal G Is there continuity?	Yes	Go to the next step.
10*		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 15.
11*	INSPECT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY Air mix actuator and climate control unit connectors are disconnected. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Switch the ignition ON (engine off or on). Measure the voltage at the following terminals (wiring harness-side): Driver-side Climate control unit terminal 2G Passenger-side Climate control unit terminal 2E Is the voltage 0 V?	Yes	Replace the climate control unit, then go to Step 15. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .)
11*		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for a short to power supply. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to power supply. Go to Step 15.
12*	INSPECT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO GROUND Switch the ignition off. Disconnect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Disconnect the air mix actuator connector. (See AIR MIX ACTUATOR REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Inspect for continuity between the following terminals (wiring harness-side) and body ground: Climate control unit terminal 1N Climate control unit terminal 1J Is there continuity?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and each actuator/sensor 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, and the common wiring harness for a short to ground. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground. Go to Step 15.
12*		No	Go to the next step.
13*	INSPECT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR OPEN CIRCUIT Air mix actuator and climate control unit connectors are disconnected. Inspect for continuity between the following terminals (wiring harness-side): Driver-side Climate control unit terminal 1N-Air mix actuator terminal G Climate control unit terminal 1J-Air mix actuator terminal E Passenger-side Climate control unit terminal 1N-Air mix actuator terminal E Climate control unit terminal 1J-Air mix actuator terminal G Is there continuity?	Yes	Go to the next step.
13*		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and air mix actuator 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, and the common wiring harness for an open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has an open circuit. Go to Step 15.
14*	INSPECT AIR MIX ACTUATOR (POSITION SENSOR) CIRCUIT FOR SHORT TO POWER SUPPLY Air mix actuator and climate control unit connectors are disconnected. Connect the negative battery cable. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 2.0, SKYACTIV-G 2.5] .) Switch the ignition ON (engine off or on). Measure the voltage at the terminals (wiring harness-side): Climate control unit terminal 1N Climate control unit terminal 1J Is the voltage 0 V?	Yes	Replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER] .) Go to the next Step.
14*		No	Refer to the wiring diagram and verify whether or not there is a common connector between climate control unit terminal and each actuator/sensor 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, and the common wiring harness for a short to power supply. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to power supply. Go to the next step.
15	VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR Can the temperatures for the driver-side and passenger-side be adjusted independently?	Yes	Troubleshooting completed. Explain repairs to customer.
15		No	Recheck malfunction symptoms, then repeat from Step 1 if malfunction recurs.