[ischmitz]

During cranking the GND signal coming from pin 14 and 15 is only about 1 - 2 milliseconds in duration. A NOID light (an LED in a fancy package) will flash very dimly but it's hard to see unless the environment is really dark.

You may want to get yourself a simple oscilloscope (less than 30$ on evil bay) to make it visible. A multimeter will not help here. If it's not present check the wiring.

Disconnect all injectors and ohm out the GRY/WHT and GRY/BRN wires on the injector connectors back to the ECU connector pin 14 and pin 15 respectively. That's all there is to it.