Parts for your 2014 Mitsubishi Asx-Tx valve

2014 Mitsubishi ASX TX Valve — what it is and when to service it

Based on technical references, a thermostatic expansion valve (TX valve/TXV) is fitted to the 2014 Mitsubishi ASX air-conditioning system. The Mitsubishi workshop manual for ASX/RVR/Outlander Sport (Heating and Air Conditioning section) details the expansion valve at the evaporator inlet, and the Mitsubishi ASA electronic parts catalogue lists an A/C expansion valve for the 2014 model range. That confirms the TX valve is relevant to this vehicle.

On the 2014 ASX, the TX valve meters refrigerant into the evaporator to match cooling demand. By sensing evaporator outlet temperature and pressure, it keeps superheat in the sweet spot so the cabin cools quickly without freezing the core. It’s the small but critical traffic controller that helps stabilise vent temps, reduce compressor load and keep fuel use and cabin comfort in check.

Owners who notice weak or erratic cooling, frost on the evaporator or pipes, a hissing/whistling at the dash, or pressure readings that don’t stack up (high low-side or starved low-side) may be looking at a sticky or blocked TX valve. Because the system is sealed and refrigerant handling is regulated in AU/NZ, diagnosis and replacement should be done by a licensed air-con tech. The under‑bonnet label will confirm refrigerant type (most 2014 ASX in AU/NZ use R134a) and charge amount.

• Best practice when replacing the TX valve includes: new O‑rings, flushing lines where appropriate, replacing the receiver‑drier/desiccant, pulling a deep vacuum, and recharging to factory spec.
• Access is typically at the evaporator inside the HVAC case, so glovebox or dash trims may need to come out. A competent workshop will also check the cabin filter, condenser cleanliness and condenser fan operation to protect the new valve and restore peak performance.

There isn’t much “maintenance” on the valve itself, but keeping the system healthy goes a long way. Have the A/C run for 10–15 minutes every couple of weeks year‑round to circulate oil, change the cabin filter on schedule, and get the system performance‑tested if cooling tails off. If contamination (black death, desiccant loss, moisture ingress) is found, expect the TX valve to be replaced as part of a broader clean‑up so the fix actually lasts.

Popular questions

Where is the TX valve on a 2014 Mitsubishi ASX?
The TX valve sits at the evaporator inlet inside the HVAC box, usually accessed behind the glovebox area. Refrigerant lines pass through the firewall to it, interior trim removal is commonly required for replacement.

What are the signs a TX valve is failing on an ASX?
Common clues include slow or inconsistent cooling, icing on the evaporator or pipes, and odd hissing at the dash. Gauge checks can show abnormal pressures. A licensed tech can confirm with temperature and pressure diagnostics.

Do you need to regas after replacing the TX valve?
Yes. The system must be fully recovered, evacuated and recharged to the correct spec. In Australia and New Zealand, refrigerant handling must be carried out by a licensed air‑conditioning technician.