Checking activation

• Connect voltage tester e.g. V.A.G 1527 B with measuring probes and connector adapters from V.A.G 1594 A between socket 2 (CMP sensor signal) and socket 1 (B+); the harness connector remains connected.
  NOTE: Connector sockets are numbered respectively on the rear side of the connector.
Fig 1: Connecting Voltage Tester V.A.G 1527 B With Measuring Probes To CMP Sensor
Courtesy of AUDI OF AMERICA, INC.
• Operate starter for a few seconds.
  • LED must blink.
  NOTE: Voltage testers do not go out completely during low current pick-up between activations by the ECM, but rather continue to glow a little and then get significantly brighter during activation.
• Switch ignition off.

If LED does not blink: