Parts for your 2020 Mitsubishi Asx-Tx valve

2020 Mitsubishi ASX TX‑valve: what it does and when to sort it

Yes, the 2020 Mitsubishi ASX uses a thermostatic expansion valve (TX‑valve). This isn’t an orifice-tube setup. Technical references that document it include the Mitsubishi Motors factory service manual for RVR/ASX/Outlander Sport (HVAC section, Group 55), the Mitsubishi ASA electronic parts catalogue listing an “Expansion Valve” for this model line, and common aftermarket catalogues (e.g., DENSO) that specify a direct-fit expansion valve for 2010–2021 ASX/Outlander Sport variants. Those sources place the TX‑valve on the evaporator assembly where the refrigerant pipes pass through the bulkhead.

The TX‑valve’s job is to meter liquid refrigerant into the evaporator based on temperature and pressure, keeping the evaporator right on the sweet spot for quick cabin cool-down without freezing up. It balances cooling performance with compressor load, which helps fuel economy and keeps things comfy on scorching Aussie and Kiwi summer days.

On the ASX, the valve is mounted at the evaporator inlet. Access is typically from the passenger side of the dash near the glovebox/bulkhead area, depending on trim and build, partial dash or HVAC case access may be required to replace it.

When it’s crook, the air‑con can behave oddly. Common clues include:

• Weak or intermittent cooling, especially after hot soak
• Frosting at the evaporator or TX‑valve area
• Erratic high/low side pressures during gauge checks
• Audible hissing or temperature swings at the vents

Replacement and care tips for the ASX TX‑valve:

• Have an ARCtick‑licensed technician (AU) or a suitably licensed technician (NZ) recover the refrigerant before cracking lines—venting is illegal.
• Confirm refrigerant type from the under‑bonnet label (most AU/NZ 2020 ASX models use R134a). Recharge to the factory charge mass.
• Always fit new OEM‑spec O‑rings, lightly lubricated with the correct PAG oil grade used by the system.
• Tighten fittings to the service manual torque spec, then evacuate with a vacuum pump and leak‑test before recharging.
• Replace the receiver‑drier/desiccant whenever the system is opened to air.
• No routine replacement interval is specified, treat the TX‑valve as a replace‑on‑symptom component.

Done right, a fresh TX‑valve restores crisp, consistent cooling and protects the compressor. For anyone chasing peak AC performance on a 2020 ASX, this small part pulls big weight.

Popular questions

Does the 2020 Mitsubishi ASX use a TX‑valve or an orifice tube?
It uses a TX‑valve. Factory service documentation and OEM parts catalogues list an expansion valve on the evaporator assembly for this model. There’s no fixed orifice tube in the ASX’s system.

Where is the TX‑valve located on a 2020 ASX?
It’s mounted on the evaporator at the bulkhead connection. Access is generally from the passenger side behind the glovebox area, some vehicles may require partial dash/HVAC case access to remove and replace it.

How much refrigerant does it take after replacing the TX‑valve?
Recharge to the exact mass on the under‑bonnet label for the specific build and market (commonly R134a on AU/NZ 2020 ASX). Always verify the charge amount and oil balance in the factory service manual.