Parts for your 2004 Honda Elysion-Tx valve

2004 Honda Elysion TX valve: what it is, where it lives, and when to replace it

Short answer: yes, the 2004 Honda Elysion uses a TX valve (thermal expansion valve) in its air-conditioning system. In models with rear air, there’s a second TX valve for the rear evaporator. This is confirmed by technical sources including: Honda Elysion (RR1–RR4) Workshop/Service Manual HVAC section describing the “Expansion Valve” at the evaporator inlet, Honda Genuine Parts Catalogue for JDM Elysion listing “Valve Assy., Expansion (Front/Rear)” within the A/C group, and OEM parts diagrams for Elysion RR1–RR4 (front and rear A/C variants) on recognised catalogues that show the valve mounted to the evaporator block. These sources align with Honda’s typical HVAC design of the era, which uses TX valves rather than fixed orifice tubes.

The TX valve meters refrigerant into the evaporator based on temperature and pressure, keeping superheat in check so the Elysion’s cabin stays cool without icing the core. On dual‑A/C Elysions, the front valve serves the dash evaporator and the rear valve serves the rear unit, balancing flow so both zones behave properly. When a TX valve sticks, clogs, or mis-meters, the telltales are weak or erratic cooling (especially at idle), frosty or sweating pipes near the firewall or rear quarter, hissing and surge noises, and pressure readings that don’t make sense. Left long enough, it can make the compressor work harder and wear faster.

It’s not a routine service item, but it’s smart to inspect or replace a TX valve if the system’s been opened, after a compressor failure, or when diagnostics point that way. Best practice looks like this:

• Recover the refrigerant, then access the valve: front is at the evaporator in the heater/A/C case (behind the dash), rear sits at the rear evaporator (rear quarter trim area on dual‑A/C models).
• Replace the valve, all related O‑rings, insulate the sensing bulb correctly, and renew the receiver/drier or desiccant pack whenever the system’s opened.
• Flush lines if there’s debris, add the correct PAG oil amount, pressure‑test with dry nitrogen, evacuate thoroughly, then regas by weight to the label spec (R134a on this model).

Because handling refrigerant is regulated in Australia (ARCtick) and requires certification in NZ, leave the job to a licensed A/C tech. As a bit of preventative care, keep the condenser clean and the cabin filter fresh, both reduce load and help prevent evaporator icing, which can mask TX valve issues during diagnosis.

Technical sources referenced: Honda Elysion RR1–RR4 Workshop/Service Manual (HVAC section: Evaporator/Expansion Valve procedures), Honda Genuine Parts Catalogue (JDM, 2004–2006, A/C group listing front and rear expansion valves), and OEM parts diagrams for Elysion RR-series showing the expansion valve fixed to the evaporator block on front and rear units.

FAQs

Does the 2004 Honda Elysion have one or two TX valves?
Most Aussie and NZ‑import Elysions with rear air use two TX valves: one for the front evaporator and one for the rear. Base models without rear A/C have a single front TX valve.

Where is the TX valve located on an Elysion?
The front TX valve sits on the evaporator inlet in the HVAC case behind the dash (access involves glovebox/centre stack removal). The rear TX valve, if fitted, is mounted at the rear evaporator unit behind interior trim in the rear quarter on the left or right side, depending on variant.

How much does TX valve replacement usually cost?
It varies with spec (front‑only vs dual A/C). Typical labour is about 2.5–4.0 hours for the front and 1.5–3.0 hours for the rear, plus parts, refrigerant, oil, and a new drier. Expect a few hundred dollars for a straightforward single‑valve job, with dual‑A/C cars and dash‑out work tracking higher. A proper quote will depend on diagnostics and access time.