95 Bonnie QDM issues

Ok i have a 95 bonnie that is sending a QDM code. What dose the QDM do and if i need a new one can i just get from a junk yard.

Thanks

Qdms are devices in the pcm that control various solenoids for engine and trans controls, normally a qdm code inidicates a short or open circuit in that particular qdm circuit or solenoid. Replacing the pcm is not the answer

You need to know whats on that Quad Driver Module so that you can test those items as the PCM has seen a problem with one of the items on that circuit...