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What is a ecc? It is not going to start if you replaced the VCM (vehicle control module) (the one by the coolant reservoir)? Until you have the vehicle towed to a GM Dealer and have the module programmed to the vehicles VIN (vehicle identification number) and mileage! YES, They will need the vehicle!

Most of the control modules in GM vehicles now come with an Electrically Erasable Programmable Read Only Memory (EEPROM) that requires programming for correct operation. Modules that may need to be programmed include (but are not limited to) Powertrain Control Module (PCM), Vehicle Control Module (VCM), Electronic Control Module (ECM), Electronic Brake Control Module (EBCM), Transfer Case Control Module (TCCM), Body Control Module (BCM), Driver's Door Module (DDM), HVAC Control Module, Instrument Panel Cluster (IPC), Memory Seat Module (MSM), OnStar, Passenger Door Module (PDM), Radio, Remote Control Door Lock Receiver (RCDLR), Trailer Brake Control Module (TBCM), Transmission Control Module (TCM), Vehicle Theft Deterrent Module (VTD), Parking assist module (UPA), Vehicle Direction Alert Alarm Warning (VDAAW), and more. The most common method to program control modules is through the DLC after the module has been installed in the vehicle. Some modules may be programmed by using an off board programming adapter and many parts suppliers now have this equipment. Be sure to verify whether a replacement module needs to be programmed before purchasing. If it does need programming make the necessary arrangements to have it programmed.

NOTE: The most common reason for this vehicle to lose spark is a failed ICM (ignition control module)