How to test a 92 525i bmw ignition coil

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Measure the resistance between terminal 1 and terminal 15 of the ignition coil.
Resistance should be 0.45 ohms (+10%) . Replace as necessary.
NOTE: Resistance cannot be measured between terminal 4 and 4a of the coil.

With the ignition "ON" test for voltage at terminal 3 of the ignition coil electrical connector (disconnected).
Reading should be 12 volts. If not check circuit between terminal 3 of the ignition coil and terminal 15 of the ignition switch for open or short. Repair as necessary.
Test circuit between terminal 2 of the ignition coil electrical connector (disconnected) and ground.
Reading should be 0 ohms. If not check circuit for opens.
While cranking the engine test for pulsating ground signal at terminal 1 of the ignition coil electrical connector (disconnected) briefly.
Reading should alternate between 0 and infinite resistance to ground. If not check the circuits to the final output stages of the Digital Motor Electronic (DME ) control unit. If the circuits are OK refer to Computers and Control Systems for testing the DME control unit.