Parts for your 2006 Honda Odyssey-Tx valve

2006 Honda Odyssey TX Valve (Thermal Expansion Valve) — What It Does and When to Replace

Technical sources, including the Honda Odyssey 2005–2010 Service Manual (HVAC section) and Honda’s OEM parts catalog, specify a thermal expansion valve (TXV) for the 2006 Odyssey. Front A/C systems use a block-type TXV at the evaporator connection, and models with rear A/C also have a separate rear TXV. This vehicle does not use an orifice tube.

The TX valve on a 2006 Honda Odyssey meters the flow of R‑134a into the evaporator based on superheat, keeping the evaporator cold without flooding the compressor with liquid. That fine control is why Odysseys use a TXV rather than a fixed orifice—better cabin comfort across changing loads, from Auckland’s winter drizzle to a scorching Gold Coast summer school run.

On the Odyssey, the front TXV mounts at the firewall where the A/C lines meet the evaporator, the rear unit (on dual A/C models) sits near the rear evaporator assembly behind interior trim in the left rear quarter. Routine services don’t include TXV replacement, it’s a fit-and-forget part until symptoms show. Tell-tales include weak cooling at idle but okay at speed, a frosty or sweating suction line at the firewall, erratic vent temps, or pressure readings that don’t respond as expected. Contamination after a compressor failure can also jam the valve.

When replacing a TXV, a licensed air‑con tech should recover the gas, cap open lines promptly, and renew the O‑rings. It’s smart practice to replace the desiccant bag in the condenser when the system is opened, and to consider doing both TXVs on dual A/C vehicles if there’s debris. Use the correct PAG oil type and quantity specified by Honda, evacuate thoroughly (deep vacuum), and recharge strictly by weight per the under‑bonnet label—guessing by pressures is asking for uneven cooling. If access is tight or corrosion is present, expect extra time for rear TXV work, as interior trim removal is required.

• Typical faults: sticking valve, contamination from compressor wear, moisture causing freeze‑up.
• Good practice: replace receiver/desiccant, flush lines (not the compressor or TXV), and leak‑test with nitrogen.
• Safety: A/C work must be done by a licensed technician due to refrigerant handling laws in AU/NZ.

FAQs

Does the 2006 Honda Odyssey use a TX valve or an orifice tube?
It uses a thermal expansion valve. Honda’s factory service information and parts catalog list a block‑type TXV at the front evaporator, plus a rear TXV on models with dual A/C. There’s no fixed orifice tube in this system.

Where is the TX valve located on a 2006 Odyssey?
The front TXV is at the firewall where the A/C pipes meet the evaporator—easy to spot near the passenger side. On dual A/C models, the rear TXV is mounted at the rear evaporator assembly behind the left rear quarter trim, requiring interior trim removal for access.

Should both TX valves be replaced after a compressor failure?
Usually, yes. If a compressor sheds debris, both TXVs can be affected. Best practice is to replace the failed compressor, both TXVs (on dual systems), the condenser desiccant, flush the lines, and then evacuate and recharge to spec.