Cars · Electronics

OBD0 16-Bit RPM Formula

RPM to 16-bit hex value conversion formula for OBD0 Honda ECUs.

Beginner

Adapted from pgmfi.org wiki

To translate engine speed (RPM) to the 16-bit hexadecimal values expected by OBD0 Honda ECUs:

ECU Hex Value = 1920000 / RPM

Excel Conversion

If you are compiling custom ROM tables in Microsoft Excel or Google Sheets, you can calculate the hex string using:

=DEC2HEX(1920000 / RPM_value)

Credits and source

Authors Anonymous PGMFI contributor

Source Adapted from OBD016 Bit RPM on pgmfi.org wiki. Licensed under CC BY-NC-SA 1.0.