same thing happened to me 3 times..kept going to dealer over a 4 month period.. he kept saying it was 1..bad gas cap....2 new gas cap allso bad...etc...etc...kept resetting the memory finally took vehicle to a different toyota dealer...he corrected the problem (has been 2 months now..no lights on) seems that the dealer (toyota)that i bought vehicle from when he changed the oil and checked the air filter..he disconneccted one vacuum line going to the air filter box...he connected it ...no more lights...it use to take approx. 30 starts to make lights go on... supposidely it is a very common problem when checking air filter..
On my 2002 Highlander...I've had this before after an oil change and knew about the vacuum line on the back side of the air cleaner. I checked and that line is connected. Anybody know where that line goes? Maybe it got disconnected on the other end.