Parts for your 2017 Mitsubishi Asx-Tx valve

2017 Mitsubishi ASX TX‑valve: what it is, where it lives, and how to look after it

Based on Mitsubishi’s Heater & Air Conditioning (HVAC) service information for GA/GA2W ASX models, the factory parts catalogue (EPC/ASA) component list, and DENSO automotive A/C system documentation for these vehicles, the 2017 Mitsubishi ASX uses a thermostatic expansion valve (TX‑valve) mounted at the evaporator inlet. These sources show the valve as the metering device (not an orifice tube) that controls refrigerant flow into the evaporator core.

The TX‑valve on a 2017 Mitsubishi ASX meters liquid refrigerant into the evaporator, matching flow to heat load so the cabin cools efficiently without icing. It reacts to evaporator outlet temperature and pressure, keeping superheat in the sweet spot. That means crisp, consistent cooling on hot Aussie or Kiwi days and less hunting or fogging when the weather turns.

For servicing, the TX‑valve isn’t a routine replacement item, but it should be considered when there are cooling complaints or when major A/C work is underway. Common clues the valve’s struggling include weak cooling at idle, super cold then suddenly warm air, evaporator icing, a noticeable hiss at the dash, or a system that cools only while driving. A technician will confirm with pressure readings and temperature measurements rather than guesswork.

• When to replace: confirmed restriction or sticking, contamination after compressor failure, or severe corrosion/leaks at the valve block.
• What to pair with it: new O‑rings (PAG‑oiled), inspect or replace the receiver‑drier (often integrated with the condenser on ASX), and flush lines if debris is present.
• Good workshop practice: nitrogen pressure test, deep vacuum, then recharge by weight to the under‑bonnet label. Use the specified refrigerant (most 2017 ASX models are R‑134a, check the sticker) and the correct PAG oil type and quantity.

Because refrigerant handling is regulated (ARCtick licensing in Australia, licensed handlers in New Zealand), TX‑valve work is best left to an A/C specialist. They’ll also follow the service manual torque specs for the block‑style valve at the evaporator and verify blend door and condenser fan operation so a marginal valve isn’t blamed for another fault.

Owners keen on prevention should keep the cabin filter fresh and the condenser face clean. Both reduce strain on the valve and compressor, helping the ASX deliver steady, quiet cooling across long kilometres.

Technical sources referenced (no external links provided): Mitsubishi Motors ASX/RVR/Outlander Sport HVAC Service Manual (Group 55), Mitsubishi ASA/EPC for 2017 ASX (evaporator/expansion valve listings), DENSO A/C systems training and component guides indicating TX‑valve use on this platform.

Popular questions

Does the 2017 Mitsubishi ASX use a TX‑valve or an orifice tube?
The 2017 ASX uses a thermostatic expansion valve at the evaporator, not an orifice tube. Mitsubishi’s service documentation and parts listings show the TX‑valve as the metering device for this model.

What are the signs of a failing TX‑valve on a 2017 ASX?
Weak cooling at idle, intermittent cold/warm swings, evaporator icing, or unusual hissing at the dash are common symptoms. A tech will verify with pressure and temperature checks to rule out low charge, a blocked cabin filter, or a lazy condenser fan.

Should the TX‑valve be replaced when fitting a new compressor?
If the old compressor failed and shed debris, the TX‑valve may need replacing along with the receiver‑drier and a proper system flush. If the system is clean and the valve operates within spec, it can often stay, but many workshops recommend replacement as cheap insurance.