The following video is one of the best I have seen for diagnosing ignition control modules and ignition coils . Although they are testing an Oldsmobile the 3800 engine is the same one that is used in the Buick Reatta.

Thanks to youTube for this information.

ATTENTION: Any advice or information found on this website should not be considered 100% accurate. Use any information you find here at your own risk. Carefully read and agree to the DISCLAIMER AND FAIR USE NOTICE before using any information found on this website.