Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Mazda CX-3 AWDFACTORY OEM SERVICE PROCEDURE
Cooling Fan Control System Inspection
- Connect the M-MDS to the DLC-2.
- Start the engine and warm it up to normal operating temperature.
- Perform the KOER self test. (See KOEO/KOER SELF TEST .)
- Verify that DTC P0480:00 is not shown and the cooling fan operates during the KOER self test.
- If the DTC P0480:00 is displayed, perform the DTC inspection. (See DTC P0480:00 .)
- If the cooling fans do not operate, proceed to the following:
- Inspect the following parts in the indicated order in accordance with fan operation conditions.
- Open circuit between battery positive terminal and cooling fan relay
- Open circuit between cooling fan relay and fan control module
- Open circuit between fan control module and ground
- Poor connection of the cooling fan relay
- Poor connection of the fan control module connector
- If there is no malfunction:
- Replace the cooling fan component. (See COOLING FAN MOTOR REMOVAL/INSTALLATION .)
- Start the engine and idle it at an engine coolant temperature of less than 97°C {207°F}.
- Verify that the cooling fan does not operate when the A/C switch and fan switch (with manual air conditioner system) are turned off.
- If the cooling fan operates, perform an inspection of the following:
- Cooling fan relay (stuck close)
- Short to power supply in wiring harness between cooling fan relay and fan control module
- Refrigerant pressure sensor
- Climate control unit
- CAN communication (PID: AC_REQ is on constantly)
- If the cooling fan operates, perform an inspection of the following:
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.