Parts for your 2002 Mazda 6-Tx valve

2002 Mazda 6 TX valve – what it does and how to look after it

For the 2002 Mazda 6 (GG/GY), a TX valve is relevant and fitted. Mazda’s workshop documentation for GG/GY models lists an “Expansion Valve” at the evaporator inlet, and removal/installation procedures for it. This TX valve setup is consistent with DENSO-style A/C systems used by Mazda of this era and is also noted in common service references such as the Mazda Global Service Information and Haynes Repair Manual for Mazda 6 (2002–2012).

On this model, the TX valve (thermal expansion valve) meters refrigerant into the evaporator, matching flow to heat load so the cabin gets steady, efficient cooling without the evaporator icing up. It senses temperature/pressure, then keeps a small amount of superheat at the evaporator outlet. When it’s working right, vent temps are cold, compressor cycling is sensible, and fuel use stays reasonable on hot Aussie and Kiwi days.

When a TX valve plays up, the Mazda 6 can blow warm at idle, get too cold then fade, or show frost on one line at the firewall. Other tell-tales include a hissing evaporator, rapid compressor cycling, or low cooling at low speeds but better on the motorway. Sticking from moisture or debris, corrosion, or contamination after a compressor failure are common culprits.

There’s no routine “service” for the TX valve itself, the focus is on system cleanliness and moisture control. Any time the air-con circuit is opened, the receiver–drier/desiccant should be replaced, new O-rings fitted, and the system evacuated for the proper time before recharging to the under‑bonnet spec with the correct oil. If a compressor has failed, it’s good practice to flush lines where appropriate and replace the TX valve to prevent re-contamination.

On the 2002 Mazda 6, the TX valve is mounted at the evaporator inlet on the firewall side. Replacement requires legal recovery of refrigerant, removal of the two A/C lines at the valve, valve swap with fresh O-rings, and a careful vacuum and recharge. Because handling refrigerant is regulated, this job is best left to a licensed air‑con technician. Doing it right restores crisp cooling, protects the new parts, and keeps the system reliable for many kilometres.

Technical sources referenced: Mazda 6 (GG/GY) Workshop Manual – Air Conditioning, Expansion Valve, Mazda Global Service Information (MGSS), DENSO Air Conditioning Fundamentals, Haynes Mazda 6 2002–2012 Repair Manual.

• Signs a TX valve may be due: uneven cooling, frosting at the firewall, rapid cycling, poor idle performance.
• Best practice when replacing: renew receiver–drier, O-rings, evacuate thoroughly, recharge by weight, leak test.

Popular questions about 2002 Mazda 6 TX valve

Does the 2002 Mazda 6 use a TX valve or an orifice tube?

It uses a thermal expansion valve (TXV), not an orifice tube. Mazda’s GG/GY workshop procedures cover the “Expansion Valve” at the evaporator, which matches the DENSO-style system design used on this model. That’s why you’ll see a receiver–drier in the circuit rather than an accumulator.

Where is the TX valve located on a 2002 Mazda 6?

It’s mounted at the evaporator inlet on the firewall side of the engine bay, where the two A/C lines enter the cabin. A licensed technician will recover the refrigerant, disconnect the lines, replace the valve and O-rings, then vacuum and recharge the system.

Should the receiver–drier be replaced when changing the TX valve?

Yes. Any time the system is opened, replacing the receiver–drier/desiccant is recommended to control moisture and protect the new parts. It helps prevent valve sticking and corrosion, and supports stable pressures and colder vent temperatures after the repair.