the ecu of the n16 is located on a higher portion, not as it used to be on the series 2 and series 3. kung nakaharap ka sa engine compartment, nsa upper left side siya (kung naka upo ka sa driver's seat, nasa kanan sya). good idea to disconnect even just the battery. kapag na disconnect mo naman ang battery, wala na signal papunta sa ecu. be sure to disconnect one battery cable. yung iba kasi ang gawa, yung positve sive fusible link lang ang binubunot. to be sure, remove the positive cable (tanda ko 10 mm lang naman na open wrench need mo