1995 buick riviera

what is the quad driver module on the 1995 buick riviera?

The quad driver is integrated into your 95's PCM. It controlls various groups of solenoids in your engine compartment, the ones I'm familiar with being your Transmission Toruqe Converter Lockup Solenoid, EGR Purge Solenoid, and Supercharger Boost Solenoid. Those are all Quad Driver Module, or QDM, #1 if I am not mistaken. On the 95, there are 4 groups of Quad Drivers controlling different things. Basically the QDM acts like a series of relays that will close a particular solenoid's circuit when the PCM tells it that the circuit solenoid needs to be in operation. In previous years, this was a module separate from the computer entirely. What's nice about the Quad Driver Module is that if it senses that there is an open or short in the solenoid or the wiring, it will shut down the Quad Driver and throw a check engine light. While this is a pain in the butt in itself, it is better than doing irreparable damage to your PCM. Are you having problems with your QDM (error codes?) that you ask this question, or just curious?