Toyota Repair: 2000Toyota Sienna, spark plug wire, jumper wire

Question
My Sienna's check engine light just came on today. It is blinking from time to time. When I have it in drive, then the idle gets rough.When I put it into neutral or park, the idle smoothes out. It is an automatic. When I get to 30 or so it shifts ok. Is it possible to diagnose without a code reader?

Answer
When the engine light blinks and from what you are describing this sounds like there is an engine misfire, this is normally due either a bad spark plug, a spark plug wire or a bad igniter coil pack, there are three of them on the "front" valve cover near the radiator, each coil fires two cylinders,it may be possible to retreive the code by putting a jumper wire in the diagnostic connector under the hood, place the wire between terminals TE1+E1 then read the codes from the check engine light, it will flash a number of times, each code will be a two digit number ie: 26 would be two flashes followed by six, I'm not sure if it will retreive a misfire code, the best way is to connect the toyota techstream computer to isolate which cylinder is misfiring. Please post a follow up with the codes and I may be able to help more.