Parts for your 2007 Toyota Vitz|yaris-Tx valve

2007 Toyota Vitz/Yaris TX-Valve: What It Does and How to Look After It

Based on Toyota’s Electronic Parts Catalogue for the XP90 platform and Toyota Repair Manual air-conditioning sections for 2005–2011 Vitz/Yaris models, this vehicle uses a thermal expansion valve (often called a TX-valve or expansion valve). DENSO air-conditioning service literature for Toyota compact vehicles of this era also specifies an R-134a, TXV-controlled system. In short: a TX-valve is fitted to the 2007 Toyota Vitz/Yaris.

On a 2007 Vitz/Yaris, the TX-valve meters liquid refrigerant into the evaporator, matching flow to heat load by responding to superheat. That keeps vent temps steady without letting the evaporator freeze. It’s a small block-style valve mounted at the evaporator connections near the firewall, and it’s part of why these little Toyotas can still blow nicely cold air on a scorcher.

When the TX-valve starts playing up, the cabin can warm up at idle, temps can surge hot–cold, or there might be frost right at the valve or evaporator inlet. A valve stuck too closed shows low suction pressure and weak cooling, one stuck open shows high suction pressure and lukewarm air. Because TX-valve issues can mimic low-gas or condenser problems, proper diagnosis with gauges, temperature readings and leak testing is the go.

If the valve needs replacing, it’s a job for someone with the right gear. The system must be safely recovered, then the A/C lines at the firewall are disconnected and the valve unbolted from the evaporator tubes. Fresh O-rings are a must, a light smear of the correct oil (PAG/ND-OIL 8 for DENSO compressors) helps sealing. Bolts should be tightened to spec (typically light torque for M6 fasteners), and the system evacuated to deep vacuum, leak-tested, then recharged with the amount shown on the under-bonnet label. As best practice, replace the receiver/drier or desiccant bag in the condenser when the system’s been opened, and fit a new cabin filter so airflow across the evaporator stays healthy.

A few practical tips owners appreciate:

• Get the A/C checked annually, regassing without fixing a leak won’t last.
• Any signs of black debris or glitter point to compressor wear—flush lines and consider a valve-and-drier combo replacement.
• After service, confirm vent temps, compressor cycling, and no hissing at the firewall.

Looked after properly, the Yaris/Vitz TX-valve will deliver crisp, reliable cooling for years, ideal for Aussie and Kiwi summers.

Popular questions

Where is the tx-valve located on a 2007 Toyota Vitz/Yaris?
It’s a block-style valve fixed to the evaporator pipes at the firewall. Most techs access it from the engine bay after safely recovering the refrigerant, disconnecting the two A/C lines, and removing the small retaining bolts. On some trims, removing parts of the cowl or the glovebox area helps visibility and access.

Do you need to replace the drier when changing the tx-valve?
Yes—whenever the system is opened, replacing the receiver/drier (or the condenser’s desiccant bag, if serviceable) is strongly recommended. It protects the new valve and compressor by trapping moisture and debris, improving long-term reliability.

What refrigerant and oil does the 2007 Vitz/Yaris use?
These models use R‑134a refrigerant and DENSO ND‑OIL 8 (PAG) compressor oil. Charge quantity varies slightly by market and spec, so follow the under‑bonnet label or the Toyota repair manual to get the correct fill. Over- or under-charging can make a good TX-valve look bad.