"Fixed" my transmission - you will NOT believe this!!
#16
Advanced
Thread Starter
I cannot say that I understand the details of how this works, but my suspicion is that with a weak battery, the cranking process during starting drops the voltage even lower, so that when I put the car in gear and try to drive, there is not enough voltage for some sensor or actuator to do its job properly. That's all I can say, since the complexity of this electronic transmission and its interactions with the main ECU are way way over my comprehension level . The only weird thing is that I would have assumed that once the engine is running, the alternator is providing a full 14 volts to the system, so there should be no low voltage condition - but again, I cannot say that I fully understand this at this point.
But it seems that with these modern cars, you should attempt no repair before first confirming a good battery. I was really REALLY close to getting another transmission this time around, and I am thanking my lucky stars that the dying battery reared its head before I did that and wasted my money (and a weekend worth of work)!
Leon
#17
Instructor
I agree, I'm glad that you've fixed your problem, but why have you needed to go through so many batteries? I can't imagine that a 430, which let's say is an 01' like mine, you shouldn't have to replace your battery at 27k... and again at 45k, and then again at 85k... I have replaced my factory battery once, and on mine and I have 133k, but I also haven't had any tranny issues. I am not saying they aren't related, but your battery should last for about 5-7 years, depending on the condition it lives in, so maybe in CA they go a lot more regularly than in MN.
The alt spins, with the crank, since they are sharing the same belt. The alternator is creating way more than 14 volts, however due to regulators it is reduced to allow the battery to charge and maintain the 12v source that powers all the cars accessories. I am just skeptical of either an alternator or a battery going out within 27k, and again at 45k, and again at 85k.
Just a point of reference, 12.6 is a full battery, >11.6 is a dead battery, mostly likely it will not turn the car over. And, I am no expert, I just work at the "stealership", and try to help people solve their problems.
The alt spins, with the crank, since they are sharing the same belt. The alternator is creating way more than 14 volts, however due to regulators it is reduced to allow the battery to charge and maintain the 12v source that powers all the cars accessories. I am just skeptical of either an alternator or a battery going out within 27k, and again at 45k, and again at 85k.
Just a point of reference, 12.6 is a full battery, >11.6 is a dead battery, mostly likely it will not turn the car over. And, I am no expert, I just work at the "stealership", and try to help people solve their problems.
#19
Advanced
Thread Starter
The alternator is creating way more than 14 volts, however due to regulators it is reduced to allow the battery to charge and maintain the 12v source that powers all the cars accessories.
#21
Lexus Fanatic
iTrader: (182)
I agree, I'm glad that you've fixed your problem, but why have you needed to go through so many batteries? I can't imagine that a 430, which let's say is an 01' like mine, you shouldn't have to replace your battery at 27k... and again at 45k, and then again at 85k... I have replaced my factory battery once, and on mine and I have 133k, but I also haven't had any tranny issues. I am not saying they aren't related, but your battery should last for about 5-7 years, depending on the condition it lives in, so maybe in CA they go a lot more regularly than in MN.
The alt spins, with the crank, since they are sharing the same belt. The alternator is creating way more than 14 volts, however due to regulators it is reduced to allow the battery to charge and maintain the 12v source that powers all the cars accessories. I am just skeptical of either an alternator or a battery going out within 27k, and again at 45k, and again at 85k.
Just a point of reference, 12.6 is a full battery, >11.6 is a dead battery, mostly likely it will not turn the car over. And, I am no expert, I just work at the "stealership", and try to help people solve their problems.
The alt spins, with the crank, since they are sharing the same belt. The alternator is creating way more than 14 volts, however due to regulators it is reduced to allow the battery to charge and maintain the 12v source that powers all the cars accessories. I am just skeptical of either an alternator or a battery going out within 27k, and again at 45k, and again at 85k.
Just a point of reference, 12.6 is a full battery, >11.6 is a dead battery, mostly likely it will not turn the car over. And, I am no expert, I just work at the "stealership", and try to help people solve their problems.
#23
Advanced
Thread Starter
My contention is that on all three occasions, it was the dying battery that created the symptoms seen at the transmission. But it was the battery, not the transmission, that was at fault. While the mileage intervals between these battery problems are short, the mean time between failures was around 3-4 years, which is short but not unheard of for a battery. Also, there was a lot of corrosion/oxidation at the battery, so perhaps that contributed even more to the low voltage condition.
I agree, this all seems far-fetched, except that the car has not hiccuped once since the new battery was put in, and my google searches show that this phenomenon has been seen by others. Again, I am not one to argue with facts on the ground, which are that the tranny works like a champ now, whereas before the battery swap it was acting up several times a day.
We'll see if this "fix" holds up, but I am happy to have fixed it with a free battery replacement rather than sinking in $3500 and a day's worth of work. But I am not a masochist, so perhaps others (who are) would prefer going through with the transmission swap instead of the battery replacement .
Leon
Last edited by lyonkster; 06-25-09 at 09:11 AM.
#24
Lexus Fanatic
iTrader: (182)
Hmmm, that is not what I am saying. I am postulating that the tranny in fact did NOT go out at either 27k or 45k (when it was replaced by dealer), or now at85k (when the dealer recommended replacing it without doing ANY check or inspection). I am guessing that the current transmission, as well as the two that were replaced, had nothing wrong with them. I am also not saying that the alternator went out - it is the original unit, and is working perfectly fine as far as I can tell.
My contention is that on all three occasions, it was the dying battery that created the symptoms seen at the transmission. But it was the battery, not the transmission, that was at fault. While the mileage intervals between these battery problems are short, the mean time between failures was around 3-4 years, which is short but not unheard of for a battery. Also, there was a lot of corrosion/oxidation at the battery, so perhaps that contributed even more to the low voltage condition.
I agree, this all seems far-fetched, except that the car has not hiccuped once since the new battery was put in, and my google searches show that this phenomenon has been seen by others. Again, I am not one to argue with facts on the ground, which are that the tranny works like a champ now, whereas before the battery swap it was acting up several times a day.
We'll see if this "fix" holds up, but I am happy to have fixed it with a free battery replacement rather than sinking in $3500 and a day's worth of work. But I am not a masochist, so perhaps others (who are) would prefer going through with the transmission swap instead of the battery replacement .
Leon
My contention is that on all three occasions, it was the dying battery that created the symptoms seen at the transmission. But it was the battery, not the transmission, that was at fault. While the mileage intervals between these battery problems are short, the mean time between failures was around 3-4 years, which is short but not unheard of for a battery. Also, there was a lot of corrosion/oxidation at the battery, so perhaps that contributed even more to the low voltage condition.
I agree, this all seems far-fetched, except that the car has not hiccuped once since the new battery was put in, and my google searches show that this phenomenon has been seen by others. Again, I am not one to argue with facts on the ground, which are that the tranny works like a champ now, whereas before the battery swap it was acting up several times a day.
We'll see if this "fix" holds up, but I am happy to have fixed it with a free battery replacement rather than sinking in $3500 and a day's worth of work. But I am not a masochist, so perhaps others (who are) would prefer going through with the transmission swap instead of the battery replacement .
Leon
#26
Advanced
Thread Starter
Thanks bud! Somewhere deep down inside I am still a little skeptical too (as in "this is too good to be true and how could the "professionals" have not found this"), but with every new day without the problem coming back, it's harder and harder to ignore the reality .
#28
Lead Lap
iTrader: (19)
Glad you figured it out....as a mechanic I see low voltage or amperage current flow as a major problem especially in these newer cars with so many computers. ****, even my 1990 turbo crx toy car fell to a "new" yellow top Optime battery that was 2 months old and became faulty only in CCA, not volts.
Anyway, again, glad you got it before the trans got replaced again.
Anyway, again, glad you got it before the trans got replaced again.
#30
Driver School Candidate
Join Date: Apr 2008
Location: IL
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Wow, awesome find! I wonder if it'll work for my amp situation hahaha. First thing that came to mind was how similar this sounds to computer problem that needs a reboot to fix things