Parts for your 2006 Subaru Impreza-Tx valve

2006 Subaru Impreza TX valve: what it does, where it is, and how to keep it happy

Technical sources confirm the 2006 Subaru Impreza uses a thermal expansion valve (TX valve) in its R‑134a air-conditioning system. This is documented in the Subaru Factory Service Manual for the 2006 Impreza (Air Conditioning section: Expansion Valve), the Subaru Electronic Parts Catalogue listing “Valve Complete – Expansion” for 2002–2007 Impreza models, and DENSO/aftermarket catalogues that list an OE‑style expansion valve specifically for this vehicle. So yes—on a 2006 Impreza, the TX valve is very much a thing.

The TX valve is the metering brain of the air‑con. It measures evaporator outlet temperature via a sensing bulb, then meters just the right amount of liquid refrigerant into the evaporator to maintain proper superheat. That balance stops the evaporator icing up, keeps vent temps nice and consistent, and helps the compressor live a long, low‑stress life. On the 2006 Impreza, the valve is mounted at the evaporator inlet behind the dash on the passenger side, so it’s not something that’s normally seen during a quick service.

There’s no scheduled maintenance for the TX valve itself, but the system around it does benefit from a bit of love. Keeping the cabin filter clean, the condenser fins free of bugs and fluff, and running the air‑con regularly (even in winter) all help the valve do its job. If cooling is weak at idle but better at speed, if vent temps surge hot‑cold, or if there’s frosting on the evaporator pipes, the valve could be restricted or sticking. Contamination after a compressor failure can also clog the valve’s tiny passages.

Replacement is a workshop job in Australia and New Zealand due to refrigerant handling rules. A proper repair looks like this:

• Recover the R‑134a, then remove the glovebox/trim to access the HVAC case and valve.
• Replace the TX valve and all related O‑rings, lubricating with the correct PAG oil.
• If the system’s been open or the compressor has failed, replace the receiver‑drier (integrated with the condenser on many Imprezas) and flush as appropriate.
• Evacuate, leak‑test, and recharge by weight to the under‑bonnet spec label, don’t guess by pressure alone.

A tidy system recharge, with the TX valve sealing and metering properly, brings stable vent temps, drier air, and quieter compressor operation—exactly how an Impreza’s air‑con should feel on a hot arvo.

Popular questions about the 2006 Subaru Impreza TX valve

Where is the TX valve on a 2006 Subaru Impreza?
It’s fitted at the evaporator inlet inside the cabin, typically accessed from the passenger side behind the glovebox area. The valve sits on the evaporator core connections, where the engine‑bay lines pass through the firewall into the HVAC case.

Does the 2006 Impreza use a TX valve or an orifice tube?
It uses a TX valve. Subaru’s factory documentation and parts listings for the 2006 Impreza specify an expansion (TX) valve rather than an orifice tube or fixed restrictor.

What are common signs a TX valve is failing on this model?
Fluctuating vent temperatures, poor cooling at idle, frost on the evaporator pipes, audible hissing at the dash, and pressure readings that swing or don’t stabilise are common clues. After compressor debris, a sticking or blocked valve is also common.