Guys,
Can anyone tell me what code 56 means for 1993 Pontiac Bonneville SSEI? My Haynes book does not list this code.

BTW, I can not find any post discussing this issue.

56 quad-driver module #2 circuit

Thanks Dan,
What is a "quad-driver module #2 circuit" lol...Can you provide advice on how to fix?
Thanks!

Not really my area, but I seem to recall that'* the driver that is used by several sensors. But I don't recall which ones. I'll see what I can find.

Found this.

The QDM is internal Pcm and contorls various components from check engine light to cooling fan to EGR soenoid and pugre solenoid. If it comes on as soon as you start the car most likely the EVAP purge solenoid is the fault.

Looks like it'* part of the EGR, so check that, the EVAP system, so check those wires, torque converter clutch and brake switch, and radiator fan relay.

Thanks Dan, as always it'* never simple (code, replace component, done). I will look into the items you suggested.