Any engine, transmission, or drive train problem which causes the check engine light or malfunction indicator lamp to turn on, will cause your vehicle to fail the smog check. Your Dodge Grand Caravan might be experiencing a problem which is only transmission related, however since the MIL is ON, it will fail the smog inspection. It should be noted, that most often, transmission faults do increase emissions when causing incorrect shifting patterns or speed faults.
Subsequently, your vehicle can qualify for the vehicle buy back program since it will fail a smog check because the malfunction indicator lamp (check engine light) is illuminated.
