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.

NO TEMPERATURE CONTROL WITH CLIMATE CONTROL UNIT (MANUAL AIR CONDITIONER) DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	INSPECT COOLANT TEMPERATURE Is the coolant sufficiently warmed up?	Yes	Go to the next step.
1		No	Warm up the engine, then go to Step 8.
2	INSPECT A/C UNIT AIR MIX SYSTEM Inspect the A/C unit air mix links, air mix cranks, and wire clamp. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .) Is there grease on links and cranks? Are links and cranks securely installed in their proper positions? Is wire clamp free of deformation? Are the above items normal?	Yes	Go to the next step.
2		No	Apply grease or install the links, cranks, and rods securely in their proper positions, repair or replace the wire clamp, then go to Step 8. (See A/C UNIT DISASSEMBLY/ASSEMBLY .)
3	VERIFY THAT AIR MIX WIRE FROM A/C UNIT IS POSITIONED SECURELY AND CORRECTLY Is the air mix wire securely installed in the correct position in relation to the A/C unit air mix links? (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .)	Yes	Go to the next step.
3		No	Adjust the air mix wire or install securely in the correct position, then go to Step 8. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .)
4	INSPECT CLIMATE CONTROL UNIT Inspect the climate control unit. (See CLIMATE CONTROL UNIT INSPECTION [MANUAL AIR CONDITIONER] .) Is the climate control unit normal?	Yes	Go to the next step.
4		No	Replace the climate control unit, then go to Step 8. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER] .)
5	INSPECT AIR MIX LINK Inspect the air mix link. (See A/C UNIT REMOVAL/INSTALLATION .) Is grease on link? Are links securely and properly installed? Are links free of obstructions and hindrances? Are the above items normal?	Yes	Go to the next step.
5		No	Apply grease to links. If any links are damaged. Replace malfunctioning part. (See A/C UNIT DISASSEMBLY/ASSEMBLY .) Then go to Step 8.
6	INSPECT A/C UNIT AIR MIX DOOR Inspect the air mix door. (See A/C UNIT REMOVAL/INSTALLATION .) Is door free of obstructions and damage? Are doors securely and properly installed? Are the above items normal?	Yes	Go to the next step.
6		No	Remove the obstruction, or install door in proper position. If any door are cracked, replace them. (See A/C UNIT DISASSEMBLY/ASSEMBLY .) Then go to the next step.
7	INSPECT HEATER HOSE Inspect the heater hoses for the following: Is heater hoses free of damage and cracks? Are heater hoses connections free of engine coolant leakage? Are heater hoses installation points on A/C unit free of engine coolant leakage? Are the above items normal?	Yes	Go to the next step.
7		No	If heater hoses connections are loose, install securely in the correct position. Repair or replace the heater hoses. (See HEATER HOSE REMOVAL/INSTALLATION .) Then go to the next step.
8	VERIFY THAT MALFUNCTION SYMPTOM OCCURS AFTER REPAIR Does the unit operate in every temperature setting?	Yes	Troubleshooting completed. Explain repairs to customer.
8		No	Recheck malfunction symptoms, then repeat from Step 1 if the malfunction recurs.