Sign In Join 



New Toyota Highlander Hybrid Owners - Give Us Your Report

143 messages,  Last post on Nov 19, 2009 at 10:23 AM

You are in the Toyota Highlander Hybrid Forum. Your Host is pf_flyer

What is this discussion about? Toyota Highlander Hybrid, Hybrid Cars, Car Buying, SUV


Messages Page 11 of 15
1
...
8
9
10
11
12
13
14
15
Prev
Next
Last
Go To Msg #
Search This Discussion

#97 of 143
Re: Completely dead after 7 days [cdptrap] by nsxwes
Dec 29, 2006 (6:48 pm)
Reply

Replying to: cdptrap (Dec 29, 2006 9:15 am)

Thank you and katzjamr very much for the information regarding resetting the idle speed control. The mpg is still in the 23/24 range and I bet that they did not do the reset.
 
Is resetting the idle speed control after a dead or disconnected battery something that is clearly indicated in the tech manual and something that a hybrid mechanic should know without a doubt or is something that can be easily missed?
 
I will be speaking to the Service Manager about this next week and I was wondering if he would immediately know what I was talking about or would his response be that I am misinformed?
#98 of 143
Re: Completely dead after 7 days [nsxwes] by cdptrap
Dec 30, 2006 (2:40 pm)
Reply

Replying to: nsxwes (Dec 29, 2006 6:48 pm)

Hi Wes,
Sure hope we are not all misinformed. You asked a very good question.
 
I did ask a local Toyota mechanic about this earlier this year (5000 mi service) when I first read about this "Idle Speed Control" issue on-line. He gave a fairly detailed explanation then and it made sense at the time. I will tell you only what I can remember. It has been 11 months now.
 
There is an "Idle Air Control System" in the HH. This system controls several valves that regulate air intake which in turn influences idle speed. The car comes with preset data for controlling the valves but it is capable of learning and adapting to actual use. It then keeps the new information in memory somewhere for subsequent use. The computer will keep adjusting this information as the car is being used. This "learned" data is lost whenever the 12V is disconnected or when it dies.
 
He said that there is really no switch that resets this system. Left alone, the engine computer will relearn all such information after sometime. During this relearning period, the car may get poorer gas mileage depending on engine conditions and driving habits.
 
He told me that as a courtesy to loyal customers, he will run a Toyota (not just HH) through its paces at various RPM to do a diagnostic. Then he takes it for a test drive at various speed. This is equivalent to a "reset". Even then, it will take actual usage conditions for the engine computer to relearn everything.
 
I do not know if this matches what other owners have been experiencing. Hopefully someone else can post what they have learnt. As our HH still has the original 12V, we have not had to do any "reset" of the ISC.
#99 of 143
Re: Completely dead after 7 days [cdptrap] by nsxwes
Jan 01, 2007 (2:10 pm)
Reply

Replying to: cdptrap (Dec 30, 2006 2:40 pm)

Thanks cdtrap, I think I will drive it for a couple of weeks and see if the system re learns my driving habits that resulted in what I consider to be very good mpg (27/28). I will let you know what happens. Thanks again for everyones help with this. Wes
#100 of 143
Re: Completely dead after 7 days [cdptrap] by katzjamr
Jan 01, 2007 (8:48 pm)
Reply

Replying to: cdptrap (Dec 30, 2006 2:40 pm)

thanks for your comprehensive reply nsxwes, the only thing i can add is i remember reading in another forum that the lexus tech will see a reading if the iac needs to be reset and can do that at the dealership. as to is it widely known by service reps, idont think so. when my sunroof motor was replaced under warranty in the 400h i asked the rep if the battery was going to be disconnected, he said usually yes, and i asked for the iac reset in that case, no one had ever brought it up to him before.
#101 of 143
Re: Completely dead after 7 days [katzjamr] by hh_newbie
Jan 02, 2007 (9:41 am)
Reply

Replying to: katzjamr (Jan 01, 2007 8:48 pm)

Sorry for piling on...but I just found your thread and the timing is uncanny.
 
We too got a HH late '05 and have been suffering with a "dead battery" problem for the past couple months (not the traction battery, but the 12V battery that starts the car).
 
We've had it in and out of the dealer throughout December and I just took it back.
 
One "interesting" comment made to me by the dealer mechanic this morning is that it's a known issue that you cannot let the car sit for more than a day without starting it. For us, if we leave it off for more than a day or two the battery typical dies.
 
The dealer is contacting Toyota and I'm hoping they replace the battery and/or upsize it.
 
Good to hear others are not have the same issue...that they can leaves theirs off for days. The whole idea seemed silly to me.
#102 of 143
Re: Completely dead after 7 days [hh_newbie] by nsxwes
Jan 02, 2007 (11:59 am)
Reply

Replying to: hh_newbie (Jan 02, 2007 9:41 am)

As I understand it, it is not the 12 volt battery that actually starts the engine. The 12 volt battery sends a message to the traction battery to start the engine when appropriate. If the 12 volt battery is dead, the message cannot be sent. Realistically, the HH should be able to sit for 3 or 4 weeks minimum without the 12 volt battery going dead. Anything less than that would not seem acceptable to me. I am very hopeful that the new 12 volt battery that was installed in my HH will cure my problem. Wes
#103 of 143
dealer mechanic comment by katzjamr
Jan 03, 2007 (2:26 pm)
Reply

Replying to: hh_newbie (Jan 02, 2007 9:41 am)

think about what that mechanic told you, toyota has made a vehicle that must be started at least every 24hrs. Please realise people say things without any basis in fact. It is not practical for many owners who travel or dont drive daily to worry about this and its not true. Your own manual asks that the car sit not longer than two weeks, and many of us have gone a month with no problem...this comment was made by a person who obviously cannot fix your problem and invented his own answer. I WOULD make him substantiate that statement and also never let him touch my car again.
#104 of 143
Re: Completely dead after 7 days [hh_newbie] by cdptrap
Jan 03, 2007 (8:02 pm)
Reply

Replying to: hh_newbie (Jan 02, 2007 9:41 am)

it's a known issue that you cannot let the car sit for more than a day without starting it.
Whoever said this is not an owner and have no clue what he or she is talking about. Ask him to prove it.
 
Most of us owners will not tolerate such limitation and you can be sure the NHTSA would have received numerous complaints if this were true.
 
Our HH sat for a week while we were gone on a trip last Winter. The car was out under a tree exposed to rain, some snow and freezing temperature. I forgot to hook up the little solar trickle charger to the 12V but when we got home, it started without a problem. Are we the only special case? I think not.
 
As long as the 12V indicator shows blue, your 12V is fine. Like all cars, car batteries do die and when they do, we will get a new one and cruise on...
 
#105 of 143
Re: Completely dead after 7 days [nsxwes] by sam71
Jan 04, 2007 (1:10 pm)
Reply

Replying to: nsxwes (Dec 23, 2006 2:09 pm)

I had two similar problems after 10 day park with car mileage at 600 & 4000 miles. I am bringing it in tomorrow for second time and this time will go to Toyota if I get no good answer. I will ask the dealer to measure the leakage current and see if it will discharge the battery after 10 days (without a resart).
 
sam71
#106 of 143
MPG back to normal by nsxwes
Jan 04, 2007 (8:17 pm)
Reply
Just a quick note that my gas mileage is back to normal now which is an average of 27 to 28 mpg. Right after the 12 volt battery was replaced it was close to 20/21, a day or two later it was up to 22/23 and now after a week is back to normal. It appears that the engine computer has relearned properly
Wes

Messages Page 11 of 15
1
...
8
9
10
11
12
13
14
15
Prev
Next
Last
Go To Msg #
Search This Discussion
To POST a message, please Sign In.

New? Join Now!

Forum Tools

Please sign in.
Email Address:

Password:

Forgot Password?

Search Forums

Enter Keyword(s)

Advanced Search

Browse by Vehicle



View All Vehicles
Advertisement
Ask the Community
See What People Are Asking

Browse by Board

Browse by Topic


View All Topics

Today's Chats

Advertisement