I connected IGN 2, 3 and 4 as signal source and same outcome. I connected another brand new ATOM and ended up with the same outcome : upon cranking and ignition of the engine, the tacho goes dead. Firmware is of latest version. Is there another way (or method) of making the tacho work without connecting the OEM ECU? This car uses all standard accessories : A/C, engine fans, fuel pump, check engine light, etc. Do you require the ATOM mapping? Andrew.