Yeah give us some more information please....the ECM is pretty robust and does not fail easily.
A new ECM needs to have the VIN code and the SKIM code programmed in as well as injector parameters etc.
Does the Red SKIS LED on left of the cluster stay ON when ignition is turned ON....should go off after a few seconds and should not flash.
Do ignition lamps came ON when key is turned but starter motor does not turn over? This could be the famous Actuator Pin Assembly Broken issue.....you can remove the Starter Relay and briefly jumper female pins inside the socket 30 to 87 while in Park or Neutral and key is in its normal ignition slot....this overrides the ignition switch, Park and Neutral interlocks....engine should turn over provided Fuse # 8 (40A) is OK.
Does it turn over in Neutral instead of Park?
Try swap over the the Starter relay and ASD relay with identical ones nearby.
If the SKIS light stays ON and the engine turns over but does not fire....remove the ASD relay and jumper female pins 30 and 87 together inside the relay socket....this overides an ASD Relay connection problem.
The 2006 CRD has a known problem with the Fuel Filter Head Mounting Bracket clamping down on the wire harness against the bulkhead....remove this bracket and check the wire harness behing it for any damage.
Is your battery fully charged, the battery terminals clean and tight, the negative battery lead clean and tight where it goes to chassis and the grounding strap from engine to chassis clean and tight both ends?
