low idle after battery change

[rainman49]

Daughter's 07 Camry with the 2AZ-FE engine has been plagued with low idle since her battery had to changed. I've read on Toyota forums that the ECU resets and default to when the vehicle was new. Some people have found relief by cleaning the throttle body. Others have left the battery unhooked for a half-hour. Some have said it relearns the vehicle's current parameters after a certain number of miles. This has been going on for more than a week. Her friend unhooked the battery for a while and hooked it back. It improved for a short period of time and then returned to the low idle. He also said the alternator tested good. I still have my doubts about the alternator. I may take it off and have it tested outside the vehicle. Any other suggestions would be appreciated. Car has 120k miles.
Thanks,
DR

 

[HerrStig]

It should idle at about 750 to 800 RPM. The idle air control (IAC) valve and the computer set the idle and the IAC can adjust for air filter condition and load, including AC load. Cleaning the throttle body works if it is dirty and the small opening for air which exists at idle is clogged by dirt. It's worth a try, though I don't see how it is related to changing a battery. The throttle pedal is connected to an sensor which controls a motor attached to the throttle plate. That could be a problem area but there should be a code set which would turn on the "Check Engine" light. Is that light on?

 

[mclasser]

Does it have drive-by-wire? If so, it doesn't have an IACV. Just resetting the battery on DBW vehicles doesn't work sometimes. You have to do a specific relearn procedure. On my Infiniti for example, you have to tap the gas pedal in a specific pattern and cycle the key on/off, known as the "pedal dance."

 

[rainman49]

It's idling at about 500-550 rpm, which makes the 4 cylinder shake. Supposedly, the ETSC-i module does away with the IAC and the butterfly is controlled by the module. My mechanic told me that sometimes they have to hook up a car to the computer and help it relearn the current conditions. I was hoping to see if I could solve this because my daughter will struggle to pay for a trip to the mechanic, although he has been great to work with heretofore.

 

[rainman49]

Car is not throwing any codes, just low idle.

 

[WylieCoyote]

My '94 Eclipse would barely idle at all after a battery disconnect, then it would re-learn where idle was after a few miles of driving. Yours seems to be the complete opposite. I'd start with a new IAC valve. The ones I've purchased ('99 & '05 Explorer) were pretty cheap.

When the alternator went out in my '05 Explorer, it idled fine until there was no longer enough voltage to maintain engine spark, and it shut completely down after a dazzling display of crazy guages & idiot lights.

 

[circuitsmith]

Cleaning the throttle body would be my first step.
Something I do ~100k miles as PM anyway.
Before my first step I'd pour a bottle of Chevron /w Techron cleaner in the gas tank.
Stay tuned for the third half of the show...

 

[BigD1]

Find out what the idle relearn procedure is, or take it to somebody that has a scanner.

When the battery is disconnected on my Oldsmobile, I have to do the long relearn procedure because I don't have a scanner. It's supposed to relearn just driving it, but I have seen go almost a week, and not relearn the idle. Takes me 10 minutes to do a manual idle relearn. 7 minutes in gear and on the brake pedal just sitting there idling. Switch off, and then another 3 minute idle in gear with brake on. Works every time for me.

 

[Pop_Rivit]

Our Subaru had a very specific way to relearn the idle after the battery was replaced or disconnected. I don't remember the procedure, but I would suspect your Camry also has an idle relearn procedure.

 

[corndogzombie]

Battery unhooked for 5 mim. Worked on my fusion

 

[The Critic]

Toyota has posted a tech tip on this issue. The fix is to disconnect the battery cable, clean the throttle body, then allow the engine to idle for 5 minutes (after warming up).

The issue is related to the learned throttle position.

 

[rainman49]

Critic, that's my Monday morning battle plan. Thanks all!

 

[rainman49]

Success! Throttle body is way on the backside of the 2AZ-FE, so I took off the air filter box, which contains the MAF sensor. Unplugged sensors and then got daughter to keep sufficient rpms to keep car running while I sprayed throttle body cleaner down the intake hose that goes to TB. Then unplugged battery for 30 minutes. Cranked it up and let it idle for 20 minutes to relearn the throttle position. Never dropped below 750 after that. Thanks again, all!

 

[Drew99GT]

Glad you got it fixed. Here is a GREAT tech tip for Toyota's with idle problems: if you spray throttle body cleaner through the throttle body, it won't touch the IAC valve. You can unscrew the magnet that control the valve, fill it with cleaner, and work it back and forth to clean out the gunk WITHOUT removing the throttle body. Many older Toyota's have a PCV fresh air hose that connect right to the IAC valve and it gets carbon build up.

https://www.youtube.com/watch?v=WsP2-HKz7vE

 

[LeakySeals]

Its very easy to remove the TB and the intake manifold in that engine. Spraying substances through the intake wont come close to what you can do with a simple removal. And.. You get to replace that pesky IMG in the process, one of the primary sources of the 2AZ-FE ruff idle

 

[rainman49]

IMG?

 

[chiefsfan1]

Originally Posted By: rainman49
Daughter's 07 Camry with the 2AZ-FE engine has been plagued with low idle since her battery had to changed. I've read on Toyota forums that the ECU resets and default to when the vehicle was new. Some people have found relief by cleaning the throttle body. Others have left the battery unhooked for a half-hour. Some have said it relearns the vehicle's current parameters after a certain number of miles. This has been going on for more than a week. Her friend unhooked the battery for a while and hooked it back. It improved for a short period of time and then returned to the low idle. He also said the alternator tested good. I still have my doubts about the alternator. I may take it off and have it tested outside the vehicle. Any other suggestions would be appreciated. Car has 120k miles.
Thanks,
DR

I thought you had to use a memory saver device to prevent this?

 

[LeakySeals]

Intake manifold gasket.

 

[InvalidUserID]

I've had that happen a few times with my '99 Civic. Once it idled really shaky after replacing the battery and more recently had a hard time starting (had to floor it while cranking) after letting it sit a month with the battery out of it.

All other times it's been completely trouble-free but something about touching the battery.