The coolant temperature sensor (CTS) on a 2005 Honda Accord is mounted in the engine's thermostat housing area, typically on the cylinder head, where the upper radiator hose attaches. It’s a small two-wire sensor that screws into the metal housing and is connected to the engine control module.
In 2005, the Accord offered two engine choices—the 2.4-liter inline-four and the 3.0-liter V6—so the exact spot can vary slightly. This article walks you through where to find the CTS for both engines and how to identify it so you can inspect or replace it if needed.
CTS location by engine type
Because the Accord used different engines in its 2005 model year, the CTS sits in the thermostat housing area for both, but the sensor’s exact mounting point differs. Look for a small modular sensor with a two-wire connector attached to the metal coolant housing behind or beside the cylinder head.
- 2.4L inline-four (K-series): The CTS is mounted in or directly adjacent to the thermostat housing on the cylinder head, usually on the passenger side of the engine bay. The sensor threads into the water outlet that handles the thermostat.
- 3.0L V6: The CTS is positioned near the thermostat housing (the water outlet) on the engine block, typically on the right side of the engine and accessible from the top/front with the air intake or other components moved aside. It also screws into the metal housing with a two-wire connector.
To confirm you’ve found the CTS, identify a two-pin electrical connector attached to a small sensor that threads directly into the housing through a brass or steel threaded port. This distinguishes it from nearby temperature sender units used for gauge or other circuits.
What you should do if you need to access or replace it
Accessing the CTS usually requires removing the engine cover (on many models) and possibly lifting the intake manifold or moving a few components to reach the housing. Always disconnect the negative battery cable before starting work and work with the engine cool to avoid burns or scalding.
Summary
On the 2005 Honda Accord, the coolant temperature sensor is mounted in the thermostat housing on the engine block, with its exact position varying by engine. In both the 2.4L I4 and the 3.0L V6, look for a small sensor threaded into the water outlet near the thermostat housing and a two-wire connector feeding the PCM. If you’re unsure, consult the vehicle’s service manual or a professional mechanic for confirmation and safe replacement.