Nissan Repair: 94 Altima check engine lite & hard shifting, inexpensive scanner, haynes manual

Question
Hello, I just bought a 94 Altima with 171,000 miles. The check engine light is on. I went to Auto Zone to have the code read & they said they didn't have a scanner to do so. Is there an inexpensive scanner I can buy to do so myself? I try to avoid the dealer charges whenever possible. I did find where the input recepticle is,(in the fuse panel compartment) right? Also, when shifting from 1st to 2nd, (Automatic) it shifts very hard. A big thump! From reading some of ur past Q & A's I now think it's most likely a bad rear motor mount? At first i thought it was a gunked up valve body.... but now I'm wondering. The tranny fluid was a bit low, so I added some Sea Foam Trans additive. I've had great success with that stuff in clearing up sticky, gunked up valve bodys before. Also.... when I start the car the overdrive light on the dash flashes 16 times everytime i start the car, but then goes off & stays off unless i push the button on the shifter handle to disengage the OD. Is it flashing me a code? HELP !  TJ

Answer
TJ,

Get a Haynes manual for your car and it will show the codes.  If you surf through the previously answered questions you will see where I have posted the anual way to check for codes.  I am not on my computer right now si I cannot repost them.  The transmission has an issue and the light flashing means something is wrong.  Cottman will do a free initial inspection so they can tell you what the codes mean on the transmission.  And, you probably do have a bad rear motor mount with the age and miles.  Not tooo hard to replace.