Parts for your 2019 Mitsubishi Asx-Tx valve

2019 Mitsubishi ASX TX Valve — What It Does and How to Look After It

Technical sources point to the 2019 Mitsubishi ASX being fitted with a thermal expansion valve (TX valve/expansion valve) at the evaporator inlet. The Mitsubishi Motors Workshop Manual for ASX/RVR/Outlander Sport (Group 55A – Heating, Ventilation and Air Conditioning) details a “thermo expansion valve” in the evaporator assembly, and the Mitsubishi ASA electronic parts catalogue lists an expansion valve for this model. DENSO OE HVAC documentation for the GA-platform vehicles also specifies a TXV-style metering device. Depending on market, the system charges with R‑134a or R‑1234yf, both commonly paired with a TXV.

On the 2019 ASX, the TX valve’s job is to precisely meter liquid refrigerant into the evaporator based on temperature sensed at the outlet (superheat). That smart metering keeps evaporator pressure stable, prevents icing, and delivers consistent, chilly vent temps even as the compressor load and ambient conditions change. It’s a perfect match to the ASX’s variable-displacement compressor and helps the cabin cool quickly without wasting fuel.

There’s no routine replacement interval for a TX valve. It’s a fit-and-forget part until symptoms show up. If the ASX’s air-con is weak at idle, swings from cold to warm, shows frost on the evaporator/outlet line, or pressure readings look skewed (high high-side with starved low-side, or erratic readings), the valve may be sticking or restricted—often from moisture or debris after another component has failed.

When replacement is needed, recovery of refrigerant by a licensed technician is mandatory (ARCtick in Australia, compliant handling in NZ). Access is typically via the HVAC case behind the glovebox. Replace the TX valve along with the O‑rings, add the correct PAG oil top-up, torque fasteners to workshop specs, evacuate for at least 30 minutes, and recharge to the under‑bonnet label spec (R‑134a or R‑1234yf as fitted). If there’s been compressor or condenser failure, it’s smart practice to flush the lines where allowed, fit a new receiver–drier or desiccant (often integrated with the condenser on late‑model ASX), and install a fresh TX valve to keep debris from coming back to bite.

Good habits help the TXV last: keep the cabin filter clean for healthy airflow, wash bugs out of the condenser fins, fix leaks promptly, and avoid stop‑leak products that can gum up the metering ports.

• Common signs of TXV trouble: poor cooling at idle, icing on the evaporator/outlet, and fluttering vent temps.
• Best practice during major A/C repairs: new O‑rings, correct oil balance, long vacuum, precise charge by weight.

FAQs

Does the 2019 Mitsubishi ASX use a TX valve or an orifice tube?
It uses a TX valve at the evaporator. Mitsubishi’s workshop literature and the parts catalogue list a thermal expansion valve for this model, which suits its variable-displacement compressor and delivers stable superheat control.

How often should the TX valve be replaced?
There’s no scheduled interval. Replace it only if it’s faulty or contaminated—often alongside a new condenser/drier and after a compressor failure. Proper evacuation, oil balancing and a weighed refrigerant charge are key to a lasting fix.

What refrigerant and oil does the 2019 ASX use?
Markets vary: many Australian/NZ vehicles of this year use R‑134a, some regions use R‑1234yf. The oil is PAG to the spec in the service manual. Always check the under‑bonnet label and follow the factory quantity by weight.