BMW X3 2005

Ignition Timing


The Digital Motor Electronics (DME) control unit carries out the operation of all ignition and fuel injection functions. Ignition timing is fully electronically controlled; there is no vacuum advance or manual adjustment. Ignition functions are calculated from internal maps and from the same sensors used for the fuel injection system. On vehicles with an automatic transmission, the control unit will retard ignition timing briefly when the transmission is about to shift up or down. For this reason, there is a data link between the DME control unit and the transmission control unit.

Since the ignition timing is controlled by the DME, checking and adjusting the timing is impossible. There is no method of setting dynamic or static timing.