Parts for your 1999 Toyota Echo|yaris-Tx valve

1999 Toyota Echo/Yaris TX Valve (Thermostatic Expansion Valve)

Technical sources confirm a TX valve is used on the 1999 Toyota Echo/Yaris. The Toyota Repair Manual for Vitz/Echo (Air Conditioning section, XP10 series) specifies a cooler expansion valve at the evaporator. The Toyota Electronic Parts Catalogue lists a “Cooler Expansion Valve” for SCP10/NCP10 models (e.g., 88515‑52xxx family). Denso A/C fundamentals also note Toyota passenger systems with a receiver–drier use a thermostatic expansion valve at the evaporator inlet—matching the Echo/Yaris layout. So, a TX valve is relevant and fitted to this vehicle.

On the 1999 Echo/Yaris, the TX valve (thermostatic expansion valve) meters refrigerant into the evaporator, maintaining the right superheat so the cabin gets reliably cold air without flooding the compressor with liquid. It reacts to temperature and pressure at the evaporator outlet, trimming flow so the system stays efficient across Aussie and Kiwi climates—from city traffic to open-road cruising.

It’s a compact, block‑style valve bolted to the evaporator at the firewall, with the hard lines coming through from the engine bay. Because the car uses a receiver–drier, the TX valve is the matched expansion device. There’s no routine maintenance on the valve itself, but its health depends on clean, dry refrigerant and correct charge. When the A/C is opened for repairs—or after a compressor failure—this is the moment to assess or replace the TX valve.

Tell‑tale signs of a sticking or blocked TX valve include weak cooling, frosty suction lines near the firewall, hissing that doesn’t settle, or pressures that are out of whack on the gauges (very low suction, or hunting). If metal debris or sludge is present, replacement is wise.

• Replace the receiver–drier any time the system is opened.
• Flush lines and condenser if contamination is suspected (skip flushing the compressor and TX valve—replace instead).
• Fit new O‑rings lubricated with the correct refrigerant oil, tighten to factory torque.
• Evacuate thoroughly, then recharge by weight to the Toyota spec with the correct oil type and quantity.

Because refrigerant handling is regulated in Australia and New Zealand, the work should be done by a licensed A/C technician. That keeps the system compliant, quiet, and properly cold.

Does the 1999 Echo/Yaris use a TX valve or an orifice tube?

It uses a thermostatic expansion valve (TX valve). Toyota documentation and the parts catalogue list a cooler expansion valve on XP10 Echo/Yaris models, paired with a receiver–drier—typical of TXV systems.

Where is the TX valve located on a 1999 Echo/Yaris?

It’s mounted at the evaporator inlet on the cabin side of the firewall, effectively behind the dash near the glovebox area, with the A/C lines passing through from the engine bay. Access usually involves working both inside the cabin and at the firewall connections.

When should the TX valve be replaced?

Replace it if there’s sticking, blockage, or contamination, or whenever the compressor has failed and shed debris. It’s also smart to fit a new TX valve if the evaporator is being replaced. Always renew the receiver–drier, evacuate properly, and recharge by weight.