Parts for your 2019 Honda Odyssey-Tx valve

2019 Honda Odyssey TX Valve (Thermal Expansion Valve)

Yes, the 2019 Honda Odyssey uses a TX valve (thermal expansion valve). Honda’s service information for the RL6 Odyssey (2018–2020) details an A/C expansion valve at the front evaporator and another at the rear evaporator in vehicles with rear climate. Industry databases such as Mitchell1/ProDemand and ALLDATA list front and rear expansion valves for this model, and major aftermarket catalogues (including DENSO and Four Seasons) publish matching application part numbers. That combination of OEM documentation and parts catalogues confirms the TX valve is relevant and fitted to the 2019 Odyssey.

The TX valve’s job is to precisely meter refrigerant into the evaporator, responding to temperature and pressure so the evaporator runs with the right superheat. On the 2019 Odyssey’s dual‑evaporator system, there’s a block‑type TX valve for the front unit and another for the rear, helping deliver steady, quick cooling across all three zones, even with changing cabin loads, idling in traffic, or during hot Aussie or Kiwi summers.

TX valves aren’t a routine replacement item, but they can stick, clog with debris or moisture, or drift out of calibration. Typical clues include weak cooling at idle, vent temps that swing hot‑cold, frost on the evaporator lines, or A/C pressures that don’t track as expected. Because the Odyssey uses R‑1234yf and a variable‑displacement compressor, correct diagnosis matters, a crook TX valve can mimic compressor or pressure‑sensor faults.

If replacement is needed, expect professional A/C service equipment: recover the refrigerant, replace related O‑rings, and renew the desiccant (the Odyssey uses a serviceable desiccant bag in the condenser). Where contamination’s present, flushing the lines and replacing the condenser may be recommended. Add the correct PAG oil amount, pull a deep vacuum, and recharge to the exact R‑1234yf charge shown on the under‑bonnet label. The front TX valve is mounted at the front evaporator and generally requires substantial dash/HVAC case access, the rear valve sits at the rear evaporator behind quarter trim. In Australia and New Zealand, refrigerant handling must be done by a licensed technician (e.g., ARCtick in AU) using SAE‑compliant R‑1234yf equipment.

• Service tips: keep the cabin filter fresh, ensure the condenser is clean, and avoid “stop‑leak” products.
• When the system’s opened, always replace the desiccant and applicable O‑rings.

Does the 2019 Honda Odyssey have one or two TX valves?

It has two: one for the front evaporator and one for the rear evaporator. That dual‑valve setup supports the Odyssey’s tri‑zone climate control and helps maintain stable temps for front and rear passengers.

What are common signs the TX valve is failing?

Slow or uneven cooling, frost on the evaporator pipes, pressure readings that are too high or too low, and vent temperatures that swing around are common. A system that cools well on the open road but fades at idle is another tell.

Is TX valve replacement a DIY job on an Odyssey?

Not really. The front TX valve typically requires major dash access, and the system uses R‑1234yf, which needs licensed handling and specific recovery and recharge gear. It’s best left to an accredited A/C specialist.