For advanced setups, tuners write custom assembly code directly into the ECU firmware. This code intercepts standard routine loops. When the ECU detects a specific button combination, the custom code changes the pointer address for core maps (like smoke maps, torque limiters, and driver wish maps) to point to a new memory offset. Benefits of EDC15 Multimapping
On many VAG (VW/Audi) group cars with EDC15, the easiest OEM-looking method is to use the cruise control stalk. A small CAN-Bus interpreter (or clever code patch) monitors: edc15 multimap