Sweet Smell from AC in 2020 Toyota Tacoma
A sweet smell coming from the AC vents typically indicates a coolant leak from the heater core. The heater core uses engine coolant, which has a sweet odor. When the AC is on, moisture can mix with leaking coolant, producing the smell inside the cabin.
Diagnosis Details
Possible Causes
Heater core leak – Coolant is leaking from the heater core into the HVAC system, producing a sweet smell when the AC is running.
Coolant leak from hoses or connections near the firewall – Leaking coolant can enter the cabin air intake.
Evaporator drain clogged – Moisture buildup can mix with residual coolant or other fluids, but less common for sweet smell.
Related OBD-II Codes
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What You Should Do
Check coolant level and inspect for leaks under the dashboard or near the heater core.
Have a professional mechanic perform a pressure test on the cooling system and inspect the heater core.
If the heater core is leaking, it will need to be replaced, which is a labor-intensive job.
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Disclaimer: This AI-generated diagnosis is for informational reference only. Always consult a qualified mechanic for an in-person inspection. AutOwner is not responsible for decisions made based on this information.
