Tach/ECU/Battery problem?
 

So a few weeks ago, I had the flooding TSB (new starter, plugs, etc) pre-emptively done. When I first got back in the car and started her up, the Tach needle swept all the way to 9K. I posted on the forum and everyone said this is normal after the ECU has been reset. OK. So yesterday, I got in my car, having not driven it in about a week, and started her up. She started right up, but the Tach needle swept to 9K, which indicates that the ECU was probably reset. I have the new battery and with the new starter, the car fired right up, so I don't think the battery was a problem, but should I be concered since the ECU apparently cleared itself over the week? I dont drive my car during the week because its winter in Boston and I have a rental through work that I drive. My 8 gets driven only when its nice out.

Errr.... is it possible for battery fluid to freeze in winter?

Car is garaged

anyone? bueller?

I don't recall my engine ever revving to 9K on startup and I have had the flash upgraded twice. If it happens on the very first start, I wouldn't know -- that would be the start when mechanic tests it (hopefully?) or at least the one to back it out of the service bay, don't you think? Then they park it and start once more to drive it out to the customer. So I figure at least 2 or 3 starts between the reset and me putting the key in.

The only needle sweep I know of is the oil pressure needle in response to the brake-taps indicates flash M or later , iirc.

the engine doesnt rev, the needles just sweeps. I posted a thread about this a while back and it was confirmed that this happens on an ECU reset. Eitherway, no one has answered my question yet. Should I be concerned??

I believe you were given erroneous information about the tach needle sweep related to a PCM/ECU reset. There IS one PCM reset prodedure that involves stomping on the brake pedal 20 times in a given period of time and that results in the oil pressure needle sweeping. For more information on PCM reset, see the sticky "ECM rest" at the top of this sections page.

I doubt that your tach needle sweep has anything to do with a PCM reset. Have the dealer check it out if it persists.

Yeh, I know about that one.

I got the orginal tach/reset info about it here on this forum from another member. The first time it happened was when I started my car up after the dealer did the TSB.

Yeah, I realize that. That's why I put up my post--to clarify the sweep thing. As far as I know or have read on this forum, a sweep by the TACH needle has little or nothing to do with reseting the PCM.

ill call the dealer later this week and follow up