Parts for your 2017 Subaru Xv-Tx valve

2017 Subaru XV TX valve: what it does and how to look after it

Yes, the 2017 Subaru XV is fitted with a thermostatic expansion valve (TX valve). This is documented in the Subaru factory service manual for the GP-series Impreza/XV (HVAC – Air Conditioning section) and reflected in Subaru’s genuine parts catalogue, which lists an expansion valve assembly for the XV’s evaporator. DENSO’s aftermarket A/C component catalogues for the same GP-platform also specify a TX valve, confirming the vehicle uses a TXV-style system rather than a fixed orifice tube.

The TX valve meters refrigerant into the evaporator based on temperature and pressure feedback, keeping superheat in the sweet spot so the aircon stays cold without flooding the evaporator. That control makes for stable cabin temps, better efficiency at idle and in stop–start traffic, and reduces compressor stress on hot Aussie and Kiwi summer days.

There’s no routine replacement interval for the TX valve, it’s a “fit and forget” component unless faults show up. Typical symptoms that point to a sticky or failing valve include:

• Weak or inconsistent cooling, especially swinging from too cold to not cold
• High or low side pressures looking wrong or hunting on the gauges
• Evaporator icing or a hissing/whistling at the dash area

If replacement is needed on a 2017 XV, it’s a job for a licensed A/C technician. The correct process is to recover the refrigerant, access the evaporator case (usually via the passenger side/glovebox area), remove the TX valve, and renew all O-rings. Good practice includes nitrogen pressure testing, deep vacuum, then recharging with the specified R134a mass and compressor oil. If the system’s been open to atmosphere, the condenser’s integrated desiccant should be renewed to keep moisture in check. Using quality parts and correct torque on line fittings helps avoid future leaks and performance niggles.

As part of regular servicing, it’s smart to:

• Replace the cabin filter on schedule and keep the plenum free of leaves
• Gently clean condenser fins and ensure fans operate properly
• Run the A/C for 10–15 minutes weekly year-round to circulate oil and keep seals happy

Those simple steps, along with prompt diagnosis if cooling drops off, will keep the XV’s TX valve and the whole A/C system performing as they should.

Popular questions

Does the 2017 Subaru XV use a TX valve or an orifice tube?
The GP-series XV uses a TX valve. Subaru’s HVAC service documentation and genuine parts listings specify an expansion valve at the evaporator, not a fixed orifice tube/accumulator setup.

Where is the TX valve on a 2017 Subaru XV?
It’s mounted at the evaporator inlet/outlet in the HVAC case behind the dash, typically accessed from the passenger side after removing the glovebox and related trims. Line fittings and a sensing element connect right at the evaporator block.

When should the TX valve be replaced?
There’s no time-based interval. Replace it if diagnostics show erratic superheat control, restriction, or internal sticking—often seen as poor cooling with abnormal gauge readings. Always pair the job with new O-rings and correct refrigerant/oil procedures.