Parts for your 2013 Toyota Bb-Tx valve

2013 Toyota bB TX valve: what it does, where it lives, and when to sort it

Based on technical sources including the Toyota Electronic Parts Catalogue (EPC, A/C section), DENSO aftermarket A/C catalogues, and OEM parts databases used by workshops, the 2013 Toyota bB (QNC20/QNC21 series) is fitted with a thermal expansion valve (often listed as “Valve, Air Conditioner Expansion”). So yes—this model uses a TX valve, and it’s a relevant service item when diagnosing air‑conditioning performance.

The TX valve’s job is to meter refrigerant into the evaporator, reacting to temperature and pressure so the evaporator runs at the sweet spot of superheat. That keeps cabin temps steady, improves efficiency, and protects the compressor from liquid slugging. In the bB, the TX valve is mounted at the evaporator inlet behind the dash (commonly accessed through the glovebox area).

It’s not a routine “replace every X km” part, but when the A/C goes off-song it’s a usual suspect. Telltale signs include:

• Weak or inconsistent cooling, especially at idle or when cruising
• Frosting at the evaporator or lines, or erratic pressure readings
• Audible hissing or a system that cools, then suddenly doesn’t

Failures are typically from contamination, moisture (ice at the valve), or debris after a compressor issue. If the system has been open or a compressor has come apart, best practice is to replace the TX valve and the receiver/drier or desiccant bag, flush what’s flushable, then evacuate and recharge to the label spec.

On the 2013 bB, replacement involves refrigerant recovery by a licensed tech, removing trim to reach the HVAC case, swapping the valve and O‑rings (lightly lubricated with the correct oil), then evacuating and recharging with the specified R‑134a charge and compatible PAG oil (check the under‑bonnet sticker or service data). A post‑repair leak check and performance test (vent temps and pressure balance) finishes the job.

To keep the TX valve happy long‑term: run the A/C regularly, change the cabin filter so airflow stays healthy, keep the condenser clean, and avoid casual “top‑ups”—proper recovery, evacuation, and charge by weight are the go. If in doubt, a qualified A/C technician in Australia or New Zealand should handle any work involving refrigerant.

FAQs

Where is the TX valve on a 2013 Toyota bB?
It’s mounted at the evaporator inlet inside the HVAC unit, typically accessed by removing the glovebox and related trim on the passenger side. From there, the lines and the valve can be reached for testing or replacement. Exact steps vary slightly by trim and market, so service data is handy.

Should the TX valve be replaced when changing the compressor?
If the compressor failed mechanically or the system was contaminated, yes—replace the TX valve and the receiver/drier or desiccant bag, then flush and recharge. This helps protect the new compressor and restores proper metering and system balance.

What refrigerant and oil does the 2013 bB use?
The 2013 bB uses R‑134a refrigerant. Oil type and fill depend on the compressor fitted (commonly DENSO with PAG oil, e.g., ND‑OIL 8), but always follow the under‑bonnet label or OEM service specs for the exact quantity and grade.