Tax Issue: Wacky Digital Odometer

As I was doing my taxes, I discovered from my handwritten mileage log record that my digital odometer in my 2006 Scion xA went berserk mid-December 2008 and didn’t straighten out again until just before the new year. It jumped 10,000 miles overnight, then hopped up & down for a week and a half like a pogo stick, before it finally settled down again. My 2009 records show it is functioning properly to date, but it shows an additional 2000 some miles more in December 2008 than the trips I made account for. If it does this every winter, it will be worthless before I get a chance to wear it out!

I live and drive almost exclusively on paved roads, though the car does live outside on our short gravel driveway. Its had other electrical problems - an unexplained electric leak that was causing the battery to discharge overnight so that I was forced to disconnect the battery at each destination to be sure I could start it at need. That seems to have self-healed by the end of the summer. Also, in December, not sure when relative to the odometer problem, all electric windows but the driver’s stopped functioning (fortunately in the up position), and still don’t work. The motors don’t even try to engage. Of course, all this is after the warranty expired. I’m the second owner - it was repossessed from the first, who apparently didn’t even bother to use the free oil change coupons in the 30,000 miles he had the car.

Since it is illegal to tamper with the odometer, how am I supposed to get this fixed? Do digital odometers need to be replaced or repaired frequently? Would it be possible to add an additional mechanical odometer to check the figures from the digital one, and if so, could I use the mechanical odometer’s readings if they were more accurate? This is the first car with a digital odometer that I’ve owned, and 2 years after manufacture seems like premature failure for an odometer. In my nearly 30 years of driving all sorts of clunkers with mechanical odometers, I never ran into inaccuracies of this magnitude.

I love my computer, but I think putting computers in cars was a really bad idea - worst possible environment for them to keep functioning, and failure can put lives at risk. Same with making everything possible electronic - electric doors and windows that fail have trapped folks in cars, resulting in their deaths during fire, flood, or accident. Give me a good manual window crank and door lever handle any day - I could fix those myself!

I got somewhat lost in your post, but there are two options:

  1. If the situation corrected itself by 31 Dec 08, then I see no problem with your handwritten log, as-is. It basically shows the beginning and ending mileages for the year, and business vs non-business use for those miles. That’s all the IRS requires, as I recall.
  2. Do an adjustment in your log with an explanation about the odometer issue. Compute your actual business use according to what you know happened, not what the odometer said.

sometimes digital odometers are defective and need to be replaced. When done, a sticker or note is provided stating what the old odometer mileage was at replacement time, and the new one is generally set at zero. Your call on whether to replace it, or see if the current one is accurate for the rest of its design life.