TMS374 ECU Decoder

A small tiny2313 MCU is used to generate the pulses instead of the PC RS232 Tx line. The TMS 374 software is in fact a simple frequency sweeper with an effective range from about 2000Hz to about 100Hz. The Tiny sweeper does exactly the same but much more better (bigger range).

After powering the device on - the LED should blink twice. Pressing the button will start the sweep procedure. LED ON - means there are pulses on the output. After reaching the lowest frequency the LED goes off and the mcu stops the generation.

Power the sweeper and ECU
Connect the GND line to any suitable GND on the ECU
Connect the Data line to the Reset pin on the 27C512 or 28F512