The model number is actually "DU1101XTPQ3". If the model number you listed this question under is correct, there is a thermal fuse located inside the control panel of the dishwasher. The part number for the thermal fuse replacement is 8193762.
If you type in your model number you can utilize the exploded view parts diagrams at pcappliancerepair.com, appliancepartspros.com or searspartdirect.com to assist you in locating the part. The fuse is listed as item 6 under the "Control Panel Parts" section.
To replace the fuse, follow these steps:
1. Make sure the dishwasher is unplugged or the breaker is turned off.
2. Open the door and remove only the top screws directly behind the control panel.
3. Remove the protective cover from back of the control panel to expose the main control board.
The thermal fuse should be mounted to the control board. If you remove it and take a resistance check, it should read close to 0 ohms, if good. If bad, replace as necessary. Make sure you follow the installation instructions on the replacement fuse.
The age of the appliance is determined by the SERIAL NUMBER. The following link explains how this is determined on Whirlpool manufactured appliances:
The SECOND DIGIT in the serial number determines the YEAR it was manufactured. The first TWO NUMBERS following that digit, represents the WEEK (52 weeks in a year) that it was manufactured. So...if I'm reading your serial number correctly, this dishwasher was manufactured January 2005.
If you have any questions about this repair, or require additional assistance, please let me know. I hope this helps you