I have a Cadilac Sedan Deville. Getting message battery volt high. What does that mean?

i hop this can help you and what you went : go to....
http://www.cadillacforums.com/forums/ht4100-4-1-4-5-4/21558-obd-i-codes-4-x-engines.html

E52=memory (history) has been lost.try ERASE all your codes and see if any come back.1.turn Ignition ON, Engine OFF.2. Push and hold the OFF and WARMER buttons until all the segments on the display illuminate and as soon as the codes start to appear, Push the OFF and HI buttons and release them until you see .7.0.
3. Turn ignition OFF.

It is having a hard time reading your chip in your key. I have the same problem on my 99. You can get them replaced but there not cheap.

the voltage regulator is faulty. it is part of the charging circuit.

http://www.autozone.com/autozone/catalog/parts/partsProduct.jsp;jsessionid=D3F17070752F91381E19E45B648C3DEC.diyprod5-b2c10?itemIdentifier=68427_74757_3439_&skuDescription=Duralast+/+Voltage+Regulator&brandName=Duralast&displayName=Voltage+Regulator&categoryNValue=15799999&sortType=&store=1160&isSearchByPartNumber=false&fromWhere=&fromString=search&counter=1&itemId=97-0&navValue=15700097&filterByKeyWord=voltage+regulator&productId=68427&searchText=voltage+regulator&categoryDisplayName=Electrical+%26+Lighting&parentId=57-0

FIRST MAKE SURE THE BATTERY HAS A FULL CHARGE !! IF NOT YOU WILL BE ASKING HOW TO REPLACE THE ALTERNATOR ! IT MAY BE BEST TO HAVE SAY PEPBOYS DO IT.. I KNOW YOU DON'T WANT TO HEAR IT BUT .. REMEMBER (ALTERNATOR) $$$$ a low battery can overwork your ALTERNATOR and burn it up ! after you have installed the battery check the power should be about 15 volts . did i help hit feedback +

If you have enough room under the car, put a wet towel by the rusty bolts and around the area. You will have to saw off the rusty bolts. The wet towel will catch sparks coming off the saw blade. Cut off the leaking metal-line, and replace with a good hose.
You could get new metal straps for the dealer.

Front seating area, driver side, under dash, mounted on passenger side of steering column

IT MEANS THAT A FAULT HAS OCCURED IN THE SYSTEM AND THE SYSTEM HAS BEEN DISABLED, TO FIND THE FAULT YOU MUST HAVE THE DEALER TEST IT FOR THE TROUBLE CODE THAT IS STORED WHEN THE LIGHT STAYS ON.

Try replacing some fuses. Check under the console for the fusebox and see if one of them is blown.

If you have the chip in the key, this is the method I used for bypassing the entire security system and never heard about it anymore: http://newrockies.ca/vatsbypass