well, this has been going on for about 2 months and i have NO CLUE what it could be... i searched the forums for answers, but i cant figure it out for my life... ill be driving and SOMETIMES when i slow down, the car just shuts off on its own. now, this is not frequent, but it happens maybe once every 2 weeks and thats enough to drive me nuts. any clues

 

have you ever replaced the maf? air filter clean? maybe tps too. maf is cheaper though. head to autozone and check for dtc?

 

dtc???

 

diagnostic trouble codes

 

interesting.. this happened to me once.. hasn't happend since though.. was about a month + ago.. good luck with the fix

-david

 

Varcity,

It's been happening to me for a while now and now seems to be happening to alot more people lately and not only in the GS, it's a low idle problem (600 RPM's and less) when we step on the brake. Unfortunately I haven't been able to come up with one solution to solve it.

My theories are:

MAF sensor
TB sensor
APP Sensor (this one seems to have solved the problem for a couple of people in other model cars)
Battery ground going bad

If you run the A/C the idle won't drop low enough to shut the car off, it's not a fix but it does help. I've had my car shut off on the HIGHWAY when I've had to hit the brake suddenly. Cleaning your throttle body will also raise the RPM's and help. But I'm still researching because I've sent my car to the dealer and they can't seem to find out what causes this. I want to find a solution and just tell them exactly what to replace. But yeah it's a PITA, not to mention dangerous.

 

well, i dont have any lights on except when the car shuts off, then all the lights on the dash turn on. so there shouldnt be any codes to read, right

 

well, i saw all those possibilities when i was searching the forums, but how would i know which one it is? is it all of them? maybe a couple or just one?? so far it has only happened when im in the car alone, but if it ever happens when other people are in the car, it can be dangerous and embarassing

 

Exactly,

No one knows if is just one symptom or all of them. The problem is any of what I listed will likely cause what's going on. Its definitely electrical and caused by stepping on the brake like the pump is just draining the energy out of the car and it dies after idling too low. (if you have people in the car, keep the A/C on as the idling doesn't drop below 800 rpms then).

 

MAF sensor
TB sensor
APP Sensor
dtc

Acronyms are confusing to those in learning modes and asking questions ...
We aren't instant messaging, it helps to spell it out.

Thanks

 

APP = Accelerator Pedal Position sensor
TB = Throttle Body sensor
MAF = Mass Air Flow sensor
DTC = Diagnostic Trouble Codes

Sorry Tammy, but this mystery is a PITA when you're going through it. After researching, it seems to be a common Lexus problem but no easy solution has been posted.

 

Try keeping the AC on, Works for me.
have exactly the same issue as you.

 

I've had this happen to me before. It usually happens after driving for a while. What I have done lately is shift into nuetral everytime i stop. I was reading the owners manual and it suggest to do this to relieve the transmission. I know it is VERY frustrating and it sucks having a nice car turn off in front of some escort. Hopefully I get my 90k done within the next few days and can ask the techs there. Ill keep a lookout for an answer.

 

Guys,

Just had to jump in here as I have been experiencing this problem also. I tried the AC thing and it really didn't help too much - but mine was only ever happening when just idling - it never happened just by using the brake.

One thing people have not yet ruled out is an alternator problem - whether it be a loose connection or just going bad.

I tried this by disconnecting the battery after the car had started and within about 10 seconds the car had died. Starts right back up everytime though. This is just food for thought for some people who cannot find an answer elsewhere.

I am going to pull mine and have it rebuilt and see if that helps my particular case.

Jonny

 

but if you disconnect the battery and the car shuts off, then wouldnt it be safe to say that the alternator IS in fact the problem?? what is the benefit of having an alternator rebuilt as opposed to purchasing a new one other than the price?? what is the price difference?? what is the turn around time on a rebuilt one?? and lastly, how long will a rebuilt one last vs. a new one?? let me know and DEFINITELY let us know how this works out for you. good luck