Battery Dead Problems?
03-10-10, 09:54 PM
#31
I've had the dead battery issue with our '94 LS 400 and again with the '01 LS 430.
Here's how to diagnose it.
1. measure the "at rest" battery drain. ( a previous poster mentioned this as well).. remove the negative battery terminal.. connect a meter in series between the battery negative and the (removed) negative cable.. set the meter to read miliamps. At rest battery drain should be less than .060 amps.
2. if you measure more than .060 amps then first make sure everything is off... i.e. ignition (well duh!), interior lights (close the doors) , mirror lights, trunk light.. hood light etc.
3. once you're sure you've eliminated any additional drain battery then grab your owners manual... flip to the back section under fuses. For example, the '01 LS 430 has a mere 85 fuse/breakers... located in 6 seperate locations (no, I'm not making this up).
4. while following the manual start removing fuses one at a time and monitoring your meter... once you've located the offending circuit then you'll have to decide replacement/repair etc.
5. additional tips:
- do one fuse at a time.. replace it before you move on to the next. (greatly reduces anxiety inducing "now it doesn't work" syndrome.
- follow the fuse diagram.. .verify the correct fuse rating for each slot. The previous owner/mechanic etc may have swapped "whatever was available"... this is just a good common sense check & peace of mind. Sometimes a mechanic (bad/dumb one) will swap a higher rated fuse to try to mask a problem i.e; replacing a 10A with a 15A. This is not only a bad idea but dangerous (can cause circuits & componentry to fry).
- spare fuses & fuse puller are (usually) located in one of the engine bay fuse panels.
- the automatic seat belt tensioners are typically the cause of excessive battery drain in Mercedes... not sure if this is common to Lexus as well.
Good luck!
Here's how to diagnose it.
1. measure the "at rest" battery drain. ( a previous poster mentioned this as well).. remove the negative battery terminal.. connect a meter in series between the battery negative and the (removed) negative cable.. set the meter to read miliamps. At rest battery drain should be less than .060 amps.
2. if you measure more than .060 amps then first make sure everything is off... i.e. ignition (well duh!), interior lights (close the doors) , mirror lights, trunk light.. hood light etc.
3. once you're sure you've eliminated any additional drain battery then grab your owners manual... flip to the back section under fuses. For example, the '01 LS 430 has a mere 85 fuse/breakers... located in 6 seperate locations (no, I'm not making this up).
4. while following the manual start removing fuses one at a time and monitoring your meter... once you've located the offending circuit then you'll have to decide replacement/repair etc.
5. additional tips:
- do one fuse at a time.. replace it before you move on to the next. (greatly reduces anxiety inducing "now it doesn't work" syndrome.
- follow the fuse diagram.. .verify the correct fuse rating for each slot. The previous owner/mechanic etc may have swapped "whatever was available"... this is just a good common sense check & peace of mind. Sometimes a mechanic (bad/dumb one) will swap a higher rated fuse to try to mask a problem i.e; replacing a 10A with a 15A. This is not only a bad idea but dangerous (can cause circuits & componentry to fry).
- spare fuses & fuse puller are (usually) located in one of the engine bay fuse panels.
- the automatic seat belt tensioners are typically the cause of excessive battery drain in Mercedes... not sure if this is common to Lexus as well.
Good luck!
My car, historically, will have a dead battery if not driven for a week or so. Leaving the key in the ignition definitely increases rate of battery drain.
I think in part it's just due to the large number of ECUs that have to be powered up even while the car is off.
One trick if you have to leave your car unused for an extended period, there is a fuse in the engine compartment fuse box labelled "DC Cut", pull that and you will have no battery drain.
12-12-11, 07:18 PM
#32
Rookie
Join Date: Feb 2009
Location: CO
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
Where did you get the 60ma figure? I was troubleshooting an issue like this on my '01 last year, and I don't remember what the at rest battery drain was but I'm pretty sure it was more than that. 60ma would only be about 1.5 AH per day.
My car, historically, will have a dead battery if not driven for a week or so. Leaving the key in the ignition definitely increases rate of battery drain.
I think in part it's just due to the large number of ECUs that have to be powered up even while the car is off.
One trick if you have to leave your car unused for an extended period, there is a fuse in the engine compartment fuse box labelled "DC Cut", pull that and you will have no battery drain.
My car, historically, will have a dead battery if not driven for a week or so. Leaving the key in the ignition definitely increases rate of battery drain.
I think in part it's just due to the large number of ECUs that have to be powered up even while the car is off.
One trick if you have to leave your car unused for an extended period, there is a fuse in the engine compartment fuse box labelled "DC Cut", pull that and you will have no battery drain.
Is pulling the “DC cut” fuse a good option if I need to park the car for more than a month? I guess there will have many things need to be reset after that? Thanks.
12-19-11, 05:18 AM
#33
Driver School Candidate
Join Date: Mar 2009
Location: United States
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
I had posted several replys to the dead battery issue back in March of 2009. In my case, it appears that the problem may very well have been the batterys themselves. The Lexus dealer replaced my battery TWICE. The second time (3rd battery) seems to have resolved the situation. I still leave the car in the garage for several weeks at a time and don't diasble anything and I haven't had a problem in almost 3 years now. Seems strange, but I can only deduct that the batterys Lexus puts in these cars the problem. I was lucky and finally got a good one, I guess.
12-19-11, 11:07 AM
#34
Rookie
Join Date: Feb 2009
Location: CO
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
So, I went to sears with the dead battery. They charged and tested it and told me it's all good, nothing wrong with the battery...they can't replace it under warranty. Hmm...
So I ordered a "battery tender plus" from Amazon the same day. At least I don't have to worry about dead battery again when I park it in my garage more than a week...
So I ordered a "battery tender plus" from Amazon the same day. At least I don't have to worry about dead battery again when I park it in my garage more than a week...
04-23-12, 01:59 PM
#35
"I don't know if anyone has the same issue, but I notice when I use the mirrors auto fold feature that's when I would walk out to a dead car. If I turn off the auto fold feature then it's fine"
My battery also died, overnight. The one thing that struck me was when I turned off the ignition yesterday, the mirrors didn't retract as they normally do. This AM the car wouldn't start and the battery voltage was down to 4.7V.
My battery also died, overnight. The one thing that struck me was when I turned off the ignition yesterday, the mirrors didn't retract as they normally do. This AM the car wouldn't start and the battery voltage was down to 4.7V.
04-30-12, 08:34 AM
#36
Driver School Candidate
Join Date: Mar 2009
Location: United States
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
Battery Dead Problems
My situation is the same as it was in my last post back in December. Still not having battery problems even though I don't drive the car (2006 LS430) for several weeks at a time. Again, in my case it seems to be a matter of bad batterys the Lexus dealer was installing.
Thread
Thread Starter
Forum
Replies
Last Post
