Parts for your 2016 Mitsubishi Asx-Tx valve

2016 Mitsubishi ASX TX-valve: what it does, where it lives, and when to service it

Yes, the 2016 Mitsubishi ASX uses a TX-valve (thermostatic expansion valve) in its air-conditioning system. This is confirmed in Mitsubishi’s Workshop Manual for ASX/RVR/Outlander Sport (Group 55 Heating & Air Conditioning), which details the “Expansion Valve” at the evaporator inlet, the Mitsubishi ASA/CAPS parts catalogue illustrations of the cooling unit and piping (showing an A/C expansion valve block at the evaporator), and common aftermarket catalogues from A/C specialists such as DENSO and major parts distributors that list an expansion (TX) valve for ASX model years around 2016.

On the ASX, the TX-valve meters refrigerant into the evaporator based on temperature and pressure, keeping superheat in the sweet spot so the cabin gets cold quickly without flooding the compressor. It’s a small part doing big work: stabilising vent temps, preventing evaporator icing, protecting the compressor, and improving fuel efficiency by keeping the A/C cycle on song.

It’s not a routine “service item” like a filter, the valve is typically left alone unless there are symptoms. Still, when the system is opened for major work (e.g., compressor or evaporator replacement), best practice is to replace the receiver–drier/accumulator, renew the TX-valve’s O-rings, evacuate the system properly, and weigh in the correct refrigerant charge as per the under-bonnet label (AU/NZ models are commonly R134a in this year). Always add the correct PAG oil quantity for any components replaced and use the workshop manual torque specs for line fittings to avoid leaks or thread damage.

Signs that point to a crook TX-valve include:

• Poor or intermittent cooling, especially at idle
• Rapid vent temperature swings or evaporator icing
• High side pressures normal but low side abnormally low or hunting
• Audible hissing at the valve area and oily residue indicating a leak

Diagnosis should be done with proper manifold gauges and, ideally, a thermometer on the evaporator outlet to check superheat. If replacement is needed, the valve is typically mounted at the evaporator inlet behind the dash (accessed from the passenger side on most ASX variants). A licenced A/C tech should recover the gas, replace the valve and O-rings, vacuum-test, then recharge by weight. After refit, confirm stable low-side pressures, steady vent temps, and no leaks. Look after the rest of the system—clean cabin filter, check condenser fins, and fix any moisture ingress—to help the TX-valve live a long, quiet life.

FAQs

Where is the TX-valve on a 2016 Mitsubishi ASX?
The TX-valve is fitted at the evaporator inlet inside the HVAC case, accessed from the passenger side behind the glovebox area on most trims. The refrigerant pipes pass through the firewall to this block-style valve. Access usually requires glovebox removal and careful separation of the A/C lines at the case.

What are the symptoms of a failing TX-valve on the ASX?
Common giveaways are weak or inconsistent cooling, evaporator icing followed by warm air, low-side pressure that’s too low or hunts, and temperature swings at the vents. A contaminated or moisture-laden system can also clog the valve, causing similar behaviour.

Does the TX-valve need regular servicing?
Not routinely. It’s replaced when diagnosed faulty or when the system is opened for major component work. When it’s out, fit new O-rings, replace the receiver–drier, evacuate thoroughly, and recharge to the exact specified mass.