I found this information on HOW TO RUN INSTRUMENT PANEL ONBOARD DIAGNOSTIC TEST. Unfortunately, I cant find the code results chart (defining err results). guess I have to call the dealership. Hope this helps.. 1.With the key in the ignition and in the off position press and hold the odometer / trip button. 2.Turn the truck to ‘On’ but do not start the truck. 3.After a few seconds the gauges will sweep from nothing to max, release the odometer / trip button. 4.The odometer should now read ‘GUAGE’, you are now in a information mode. 5.Start the truck 6.Now every time you press the odometer / trip button it will cycle through the information available. 7.When you shut the truck off the odometer will go back to showing mileage. GAGE - Carries out gauge sweep of all gauges, then displays the present gauge values. Also carries out the check sum test on ROM and EEPROM. All segments illuminated. Illuminates all odometer segments. bulb Illuminates all micro-controlled lamps and LEDs. r #### Returns to normal...