Parts:

- ECU from 99 Accord LX 4cyl 5-speed (F23A1)
- ECU from 00 Accord EX 4cyl 5-speed ULEV (F23A4)

Problem:

Replaced F23A4 ECU with F23A1 ECU and now the temp gauge in the instrument cluster does not work. Swapped back to F23A4 ECU, and the gauge works as normal. Possible pinout discrepency between the two ECUs?

 

C26 ECT, I show both on the same pin.

 

Thanks Duane. Looks like I've got some troubleshooting to do...