Parts for your 2015 Subaru Impreza-Tx valve

2015 Subaru Impreza TX valve: what it does, when to replace it, and how to keep the air‑con sweet

Technical sources confirm the 2015 Subaru Impreza uses a thermal expansion valve (TXV), not an orifice tube. This is documented in the Subaru Impreza 2012–2016 Service Manual (HVAC section), Subaru Genuine Parts catalogue listings for the Expansion Valve (e.g., 73520FJ000 for many 2012–2016 Impreza variants), and multiple aftermarket catalogues from major A/C suppliers that specify a TXV for this model.

The TX valve is the metering brain of the Impreza’s air‑con. It regulates how much liquid R‑134a refrigerant flows into the evaporator under the dash, responding to temperature and pressure to keep the evaporator cold without freezing. When it’s working properly, you get stable vent temps, quick cool‑down, and a compressor that isn’t overworked.

Signs it’s time to look at the TXV include weak or wildly fluctuating cabin cooling, frost on the evaporator line, hissing or hunting at the vents, and odd gauge readings (very high high‑side with starved low‑side when stuck closed, or low high‑side and elevated low‑side when stuck open). Because these symptoms can overlap with low charge, a clogged drier, or a tired compressor control valve, proper diagnosis with manifold gauges and temperature probes is essential.

During servicing, the TXV isn’t a routine replacement item, but it’s smart to inspect for oil stains at the valve and lines, check sensor bulb contact/insulation, and verify stable superheat via pressure/temperature readings. If the system has been contaminated (compressor failure, moisture ingress) or opened for major work, replacing the TXV and the receiver/drier (the Impreza typically uses a desiccant cartridge integrated into the condenser) is good preventative maintenance.

Replacing the TXV is a job for a licensed air‑con technician in Australia or New Zealand, as refrigerant recovery is mandatory. Typical steps are:

• Recover refrigerant and isolate the battery.
• Access the HVAC case (usually via the glovebox area) to reach the valve on the evaporator inlet/outlet.
• Remove lines, catch and replace O‑rings, swap the TXV, and refit with the correct PAG oil on seals.
• If the condenser has an integrated drier, replace the desiccant bag or condenser as applicable.
• Pressure test with dry nitrogen, evacuate to deep vacuum, and recharge to the under‑bonnet spec with R‑134a.

A fresh cabin filter and a clean condenser face help the TXV do its best work. Get the pressures and charge right, and the Impreza’s air‑con will stay crisp through Aussie summers and Kiwi road trips alike.

• Does a 2015 Subaru Impreza have a TX valve or an orifice tube?
  It uses a thermal expansion valve (TXV). Subaru’s service information and parts catalogues list an expansion valve at the evaporator for the 2015 Impreza, not an orifice tube.
• What are the common symptoms of a failing TX valve on this model?
  Inconsistent vent temperatures, slow cool‑down, frosting on the evaporator line, and abnormal pressure readings. A stuck‑closed TXV starves the evaporator, stuck‑open can flood it, both hurting cooling performance.
• Should the receiver/drier be replaced when changing the TX valve?
  Yes. Whenever the system is opened, replace the receiver/drier or the desiccant bag in the condenser (as applicable) to control moisture and protect the new parts.