Honda Engine Coolant Temperature (ECT) Sensor 37870-RTA-005

Honda Engine Coolant Temperature (ECT) Sensor – 37870-RTA-005

This is the genuine Honda Engine Coolant Temperature (ECT) Sensor, part number 37870-RTA-005. If you're chasing weird temp readings, rich/lean issues, or random cold/hot drivability problems, this is usually where you start. The ECT sends real-time coolant temp data to the ECU so it can control fuel, ignition timing, cooling fan operation, and overall engine behavior the way Honda intended.

On many cars—like the 2006–2011 Honda Civic Si—the ECT sensor sits near the thermostat housing on the block. Years of heat cycles, coolant contamination, or internal failure will skew the signal. In the real world that looks like a bouncing temp gauge, trash fuel economy, hard starting when hot or cold, or even an overheating situation because the fans don’t kick on when they should. A fresh OEM Honda ECT sensor replacement brings the readings back in line and lets the ECU do its job again.

This is a Genuine Honda ECT sensor built to OEM spec for thread fit, connector engagement, and long-term electrical reliability. Whether you’re clearing a check engine light, sorting out a cooling issue, or just doing preventative maintenance on a high-mile Honda or Acura, this is the correct OEM Honda ECT sensor to buy for a huge range of late-model applications. We run this exact style sensor on our own cars for anything from daily driving to track use.

Key features

• Genuine Honda engine coolant temperature sensor (37870-RTA-005)
• Sends accurate coolant temp data to the ECU so fueling and timing stay on target
• Controls cooling fan operation and helps keep engine temps stable under load
• Proper fix for bad sensors causing poor MPG, rich/lean conditions, or overheating
• Meets OEM Honda fit, function, and reliability standards — not a cheap no-name copy

Vehicle fitment

• 2013–2015 Acura ILX
• 2007–2026 Acura MDX
• 2017–2021 Acura NSX
• 2007–2025 Acura RDX
• 2009–2012 Acura RL
• 2014–2020 Acura RLX
• 2007–2014 Acura TL
• 2015–2025 Acura TLX
• 2009–2014 Acura TSX
• 2010–2013 Acura ZDX
• 2008–2017 Honda Accord V6
• 2018–2022 Honda Accord
• 2006–2015 Honda Civic Si
• 2012–2015 Honda Civic EX / LX / DX
• 2016–2021 Honda Civic Si / 1.5T
• 2010–2015 Honda Crosstour
• 2007–2011 Honda Element
• 2007–2008 Honda Fit
• 2016–2022 Honda HR-V
• 2007–2026 Honda Odyssey
• 2019–2026 Honda Passport
• 2009–2025 Honda Pilot
• 2009–2026 Honda Ridgeline
• 2006–2009 Honda S2000

If your temp gauge lies, the fans act drunk, or the car runs poorly hot or cold, it’s time for a Honda engine temperature sensor you can trust. Buy Honda 37870-RTA-005 sensor here as a Genuine Honda ECT sensor for sale. This is the OEM Honda ECT sensor you want when you’re shopping Honda coolant temp sensor buy, OEM Honda ECT sensor online, or any Acura ECT sensor purchase for the models listed above. Install it once, clear the codes, and your cooling system and fueling strategy go back to behaving like they should.