Hello folks, I have a problem that is difficult to pin down. I have a 2004 prius. I recent replaced the battery with the yellow optima and this fixed the need to jump my prius often. About two weeks later this new problem popped up. Twice it has not let me in the car without the mini-key. Then it would not start. The first time I got the red triangle. Then it started and ran. The check engine light came on. I reset the check engine light from the procedure I saw here and the problem went away for a short time. Now the car has reset the MPG and miles driven as well as turned back on the reverse beep four seperate times. I am not confident this can be diagnosed by the dealer because it is on consistent and I reset the check engine light. Do you have any advise or solutions>
I'm not sure but I have a hunch that when you disconnected the power when you replaced the battery that allowed everything to go back to the factory settings, not sure why the locks and the key would work that way though?
Thanks for the reply, but I connected the car to an auxiliary 12V supply and this did not happen for about 2 weeks after I changed the battery.
I suggest that you disconnect the 12V battery, then fully charge the battery. Then reconnect the battery and see if that helps.
Just wanted to update with the solution. It was a loose negative battery cable. I should have noticed it before but, the negative cable on the battery actually seats below the top of the battery post. If this is not done the clamp will tighten before it secures on the post. I hope this saves someone else the trouble.
Oooh, good catch. That could have been sparky. Considering the less than ideal situation the battery's been in you may still want to give it a touch up with a charger. - D
