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Where Is the Thermal Expansion Valve Located?

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on December 14th, 2023

Reading Time: 3 minutes

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1. Q: Where is the Thermal Expansion Valve Typically Located?

2. Tips on How to Access the Thermal Expansion Valve

Q: Where is the Thermal Expansion Valve Typically Located?

A: The thermal expansion valve (TXV) is the part of your vehicle’s air conditioning (A/C) system that controls the system’s pressure, fluid flow rate, and evaporator output temperature. The exact location of the thermal expansion valve often depends on the vehicle’s make and model.

The thermal expansion valve on older vehicles is located inside the evaporator case on the liquid line with its sensor tube connected to the suction line (see photo on the left). But on newer vehicles, the TXV is an aluminum block style valve mounted at the engine compartment bulkhead (firewall) so it can be replaced without removing the instrument panel (see photo on the right). | Image Source: Richard McCuistian

thermal expansion valave inside the dashboard near the evaporator core for 2003 2007 honda accord — If you own a 2003-2007 Honda Accord, you’ll find the thermal expansion valave inside the dashboard near the evaporator core but it is a block style TXV that can be accessed from within the engine compartment (see photos). | Image Source: Richard McCuistian

The thermal expansion valve on a 2005 Toyota Sienna, on the other hand, can be found mounted onto the vehicle’s A/C unit. It’ll be on the cabin side of the A/C housing.

Tips on How to Access the Thermal Expansion Valve

Accessing the thermal expansion valve can be a difficult and complex project best left to a professional mechanic. Removing the valve requires a depressurized A/C unit, which you need expert tools to perform. The released gas is particularly dangerous as well.

You might need to remove the dashboard and center console entirely before even catching sight of the thermal expansion valve. In addition, you need to seal the system after removing the valve because moisture might enter the system if you don’t. After replacing the valve, the A/C system will need a recharge.

About The Authors

Written By

CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By

Richard McCuistian

Technical Reviewer at CarParts.com

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.