losing tune due to battery?
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From: Portsmouth, VA
losing tune due to battery? I just installed a cam and have tuned the car to pretty much where it needs to be. Everytime I start the car my car's gauges reset and my trip odometer goes back to '0'. Does this mean that I'm losing my tune? It's always a little hard to start and will take a few minutes to "learn the idle" again. I have a Odyssey lightweight battery and my car is a 1999. My friend had an issue with his car resetting with the same battery. 99's had the TSB I believe with low voltage to the cluster causing the odo. to reset. A new battery cured this issue back before I got the lightweight battery. Any ideas?
Not losing the tune per se, but resetting the
fuel and idle trims that were learned to get it
straight up. If you massaged the idle settings
the loss of trims would not bother it so much.
But sounds like there is such a thing as "too
light" in the battery.
If you had a scheme where the PCM had some
reserve power maybe it could ride out the
voltage sag during cranking, but there's more
weight. Might want to observe battery terminal
voltage and the IGN voltage during cranking,
see if there are any wiring drops that could be
cleaned up on the cheap and let you get by
with the lightweight battery.
I was looking for info on the next larger than
680 Odyssey, myself (like whether it's good
enough to not do this).
fuel and idle trims that were learned to get it
straight up. If you massaged the idle settings
the loss of trims would not bother it so much.
But sounds like there is such a thing as "too
light" in the battery.
If you had a scheme where the PCM had some
reserve power maybe it could ride out the
voltage sag during cranking, but there's more
weight. Might want to observe battery terminal
voltage and the IGN voltage during cranking,
see if there are any wiring drops that could be
cleaned up on the cheap and let you get by
with the lightweight battery.
I was looking for info on the next larger than
680 Odyssey, myself (like whether it's good
enough to not do this).
Thread Starter
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From: Portsmouth, VA
voltage dips 7-8 volts when cranking (gauges reset) and then starts but is really rich. idleing oscillates trying to find where it wants to be and untill the car warms up and the bank 2 O2 sensor reads low (650ish mv) (880-890mv O2 bank 1). after 5 or more minutes the idling will relearn itself again.
Those batteries have caused problems in the past due to ultra low voltage during cranking. Even if it sits for a few days, the alarm, pcm ect will drop the battery voltage over a volt. The best fix a friend did for his Z was install an automatic trickle charger that he plugs in while its parked. However if its resetting every time you start the car, even after repeated driving cycles during the same day I don't think it would help you out.
As stated above the tune will stay but fuel trims and iac trims wont if there is a voltage loss. If you want to keep the current battery the best advice is to get the trims as exact as possible so minimal learning is needed
As stated above the tune will stay but fuel trims and iac trims wont if there is a voltage loss. If you want to keep the current battery the best advice is to get the trims as exact as possible so minimal learning is needed
Thread Starter
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From: Portsmouth, VA
thanks guys. well i went and put my other battery back in and so far so good. no more resetting of the odometer and i think it may be idling better when i restart. i got a new O2 that i may install here soon and am hoping that will help some
