Diagrams find the ECU ID for a car it will be located in one of three places, and this guide will continue to go in depth for various makes and models towards the end of the page.

The number starts with 37820 and for example the full number will look like this 37820-RRB-A12

The ECU ID is going to be usually in one of three places here is the answer in the order of likelihood for where it is found:

#1 Location: On the passenger side under the floormat, and under the carpet behind a “kickplate” as shown below:

#2 Location less likely but possible, close to where the other location is but here:

#3 Location: is under the hood, and its location is illustrated in the diagram below:

ECU Locations in order by location, model type, and year

  1. Passenger footwell – Civic, Accord, CR-V (2006–2010)
  2. Behind center console Accord (2006–2012)
  3. Behind glove box / dash – Civic, Accord, CR-V (2010–2015)
  4. Engine bay (near battery/fuse box) – Civic, Accord, CR-V, Pilot, Ridgeline (2012–2024)
  5. Firewall (engine bay) – Civic, Accord, Pilot (2008) (2020)
  6. Under cowl (windshield area) – Civic, Accord (2016–2024)
  7. Driver footwell – Civic (2006) (2011, rare)
  8. Integrated fuse box module – Civic, Accord, CR-V (2018–2024)

Potential ECU Locations in order

Searching any 2006–2024 Honda, check in this order:

  1. Passenger footwell (under carpet/panel)
  2. Behind glove box
  3. Behind center console
  4. Engine bay near battery/fuse box
  5. Firewall or under cowl
  6. Integrated fuse box (newer cars)

To pull up the ECU ID using Ktuner, follow these steps:

  1. Open Ktuner Software: Launch the Ktuner software on your computer.
  2. Access Tools: Click on the “Tools” menu in the software.
  3. Select Ktuner Unit Info: Choose the “Ktuner Unit Info” option.
  4. Check Software Number: Look for the number under the “Software” column to find the ECU ID.