Indicator Light Problem

For the past couple of months, the check engine and seatbelt light in my 318ti have been on while I am driving. I have had my mechanic check my car and he could not find anything wrong with the engine. He said that BMW is known for their electrical problems. My question is--does anyone know how much it would cost to repair this type of problem? I live in California and my car needs to have a smog test, but I was told that it would fail the test since the indicator lights are on. Any advice would be appreciated. Thanks!

This website has the item you need to reset your light if you really want to do it with no service being done to pass your test.
http://www.bmwtips.com/
They have all the reset tools but they can get costly. It is good though if you change your own oil.

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