Cadillac Repair: 1994 Cadilac DeVille quits then wont restart, negative battery cable, negative cable

Question
My 1994 cadillac will quit while going down the road.  I have had this happen 4 times in less than a month.  The first three times we disconnected the battery a few minutes then waited atleast 8 hours before we tried to restart it and it ran fine.  Last nite we didn't disconnect the battery and it wouldn't restart this morning.  We know it has something to do with electronics but are at a loss as to what.             The diagnostic codes it came up with last nite were  PO13, PO17, PO52, IO39, and IO52.  If you can help we would be most grateful.
             Thank you

Answer
Hi,Dennis
 A few things can cause your complaint but ill outline the most obvious ones first,then we can go from there to elliminate possible ones and narrow down to what is causing the problem.
 The main cause could be a loose ground the reason being is that the codes P013 is rear O2 sensor not ready and the P017 is ft O2 sensor not ready,what the codes mean is that both the ft and rear O2 sensor heater ckts are not responding,usually this indicates a ground ckt fault or an open O2 heater ckt either the fuse or the voltage ckt from the PCM is open,what has me suspect is that you also have an intermittent stall problem and no start,may be the PCM is failing the ground ckt also,heres the clincher,both the O2 heater ground ckts and the PCM ground ckt share the same ground which is G103,so lets repair or diagnose the grounds first that may solve the whole problem.
 First check that the battery cable connections are clean and tight,now trace the battery negative cable,this leads from the battery to the side of the engine block just behind the starter motor ft part of the engine you'll need to lift the car up a bit to gain access under the car,if you look directly to the rear of the starter there will be a stud with a locknut on the engine block the negative battery cable attaches to that stud,check and make sure it is clean and tight,and i mean tight,i have had many that were loose and caused your same problem,if it is loose i believe that is what is causing your complaint,if all checks good there,then go to G103 which is located near and on the side of the right underdash you will need to remove the rightside side kick panel,you will see just under the PCM and attached to the side of the dash black wires some with a white tracer bolted to the body,remove that ground and clean to bare metal discard the star washer if equiped and reinstall,reroad test to see if it cured the complaint,let me know if this doesnt help or if it worked and we'll go further into diagnosing it,Thanks


ED