Normally after turning the the key on and before the engine cranks the check engine light comes on to let you know the light works. Recently mine has started flashing. I was told it is showing a "Hard" code. I checked what codes the computer threw and only get a 12 which means there is no error code stored. Does anyone have any knowledge of this problem.

Make? Model? Year?

1986 Camaro Z28. (originally had 305TPI motor but now has 350TPI) 86 ecm with 350 hypertech thermomaster chip.
Note: when checking the codes I got a 45 that is for rich mixture at O2 sensor. Unplugged connection at battery which reset ecm but did not stop light flashing when ignition is on. Car runs great, Service engine light goes off when cranked. Noticed a little gas mileage dip lately but that could be from my lead foot.

Hey Dave! you asked for more info and then did not reply.:(

I don't spend as much time here as I used to. Not sure what to say. I would imagine that a flashing light would yeild a code other than 12. Did this behavior start suddenly or after installing the hypertech chip. Just wondering if it is a hypertech "feature". Sorry I don't have much to offer.

Yeah, I'd say go back to the stock chip and try it.

I've seen many strange things with aftermarket PROMS.

I've had the hypertech chip for about 6 months. The problem just started one day about 2 weeks ago. Went out to the car to go to work one morning and all of a sudden this light is flashing.

Normally after turning the the key on and before the engine cranks the check engine light comes on to let you know the light works. Recently mine has started flashing. I was told it is showing a "Hard" code. I checked what codes the computer threw and only get a 12 which means there is no error code stored. Does anyone have any knowledge of this problem.
The flashing means thats its looking for a code, and you are getting 12 because there is no error code. Do you have anything plugged in to the data port.

No there is nothing plugged into the data port. I tried replacing the chip with the stock chip I still have and it
did not help. I notice the light is grounded and comes on when the circuit is completed somewhere. Will try a different computer this coming weekend and see if that fixes it.