Why does my top load whirpool washer restart on its own after it finishes the last rinse and spin cycle. It does this on all settings, delicate, normal or heavy.

Hi, a UL error code means a load not balanced. The washer is running a load-balance correction routine. Please allow the washer to continue. If the dial is flashing and the washer has stopped, redistribute the load, close the lid, and press START/PAUSE.

Linda. I know nothing about this washer, but I did get this info from the attached link, you may still have to call a tech.
Put into diagnostics (left, right, right, right, left, right) @ done you see errors, @ spin you run calibration(this will clear codes and reset board). good luck
http://forum.appliancepartspros.com/washer-repair/537059-whirlpool-cabrio-washer-not-completing-spin-cycle.html

F51 error code is a motor rotor position sensor failure or a lower harness problem. You need to check the motor in manual test mode, not automatic test mode. This will check the hall sensors and do a spin test: Be sure the washer is in standby mode (plugged in with all indicators off; or with only the Clothes Clean or Done indicator on). Select any one button (except POWER, START, STOP, and PAUSE/CANCEL) and follow the steps below, using the same button: Press/hold 3 seconds. Release for 3 seconds. Press/hold 3 seconds. Release for 3 seconds. Press/hold 3 seconds.

If this test mode has been entered successfully, all indicators on the console are illuminated for 5 seconds with 88 showing in the Estimated Time Remaining two-digit display. During the 5 second wait time with 88 showing in the display, press the same button once. You should be in manual test mode. If the button is not pressed within 5 seconds, the automatic test mode begins. The Rotor Position Sensor uses Wash, Rinse, and Spin indicators to detect the three hall sensors. Console can have up to two of these indicators on at the same time when the tub is not moving. Open the lid and rotate the basket by hand. The Wash, Rinse, and Spin indicators should toggle on and off according to the direction the tub is being turned.

SPIN TEST: Make sure lid is down. Press and release: 2nd RINSE or EXTRA RINSE. The lid locks and the lid lock indicator turns on. Press and release; SPIN SPEED, WATER LEVEL, or LOAD SIZE. The motor/basket spins at 23 rpm. Press again, motor /basket spins at 530 rpm. Press again, motor/basket spins at 950 rpm. Press again and motor turns off.

From:
http://www.applianceblog.com/mainforums/threads/32879-Whirlpool-Cabrio-UL-F51-Error-Codes

Ideally, you just run the washer without any detergent and it'll rinse out all the soap. Try that first. My Cabrio started doing that all the time, then stopped spinning out all the water. It had a host of problems and I opted to replace the washer. Hopefully the water rinse will fix the problem for you.

Depending on model there not much, I usually hot wire mine..just take the switch off and connect the wires together with a wire nut...

check for objects in the tub such as hair pin ,nail etc...

Bad pump...

Hi, there. While we cannot assist with repairs I can offer links to our troubleshooting, use and care guides, replacment parts, parts lists, and service line should that be necessary. We hope this helps.
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That error means that it is sensing an OVERLOAD. If it does this when it is empty, then there is something causing the error. IT could be something stuck in the drum around the seal or the bearing or it could be the bearings itself

1.), Pump may be bad. Check voltage to water pump in Spin Cycle. If you have voltage at the pump, but it does not run, replace the pump.

2.) If you have voltage to the water pump, and can hear or feel it running, cut power off, and remove the boot which is directly below the wash bin. The boot empties into the water pump. You will need long needle nose pliers or better, use water pump pliers to remove the straps holding the rubber piping to the pump and the boot. Remove debris from the boot, i.e., bobby pins, coins, socks, pens, keys, etc.

3.) If no voltage comes to the pump in spin cycle, you may need a new timer.

4.) Install a new belt on the motor pulley. You will regret not replacing the belt later.