Low rpms with a new battery - Toyota Yaris Forums

jaimico · 03-22-2010, 10:37 PM

Yesterday my 2008 yaris sedan battery just past the way, and I replaced it with a bigger model (from 350 to 500 cca), since I could not find the same size or capacity as the original.

To my surprice, after replacing the battery, I started the car right away, but the rpms just when to the minimum, like 300-500 at idle (normally are around 700), it was like having a 3 cilinder engine, let it run for a while, but did not change, so i took it for a good run, and still the rpms where dropping at idle, and suddenly it just came back to normal.

Today i had my 50K maintenance, and when I came home disconected the battery to adjust the supports, and when I started the car again , the same problem again, but this time at a smaller rate (the rpms where around 500 know).

So, is it something with the car computer the need to adjust after a while, or what??, since the alternator was chargin normally.

yaris-me · 03-23-2010, 03:02 AM

The ECU is adaptive and it will adapt to your driving style. When you disconnect the battery the ECU will reset to default. After running a while it will adapt again.

Yaris Hilton · 03-23-2010, 10:40 AM

Also, if the new battery wasn't fully charged, drawing heavy charging current could drag the idle speed down. I'd think the ECU would regulate the idle speed, but people notice fluctuations when the AC compressor kicks in and adds load...

jaimico · 03-23-2010, 10:41 AM

Well that one is new, today I came back to normal, thanks for the tip.

jaaf · 04-05-2010, 08:44 AM

I'm facing the same problem with my 2006 yaris sedan 1.0 after changing battery terminals.. if a good run will solve my problem too?

TheSilkySmooth · 04-05-2010, 01:40 PM

Its just the ecu relearn. thats all. No Problem - unless it NEVER comes back.

jaaf · 04-06-2010, 11:12 PM

Quote:

Originally Posted by TheSilkySmooth

Its just the ecu relearn. thats all. No Problem - unless it NEVER comes back.

how much time ECU will take to relearn? because the problem is still there....

kazama82 · 04-08-2010, 09:35 AM

few days..

jaimico · 04-08-2010, 06:17 PM

the more you use the car it will go away sooner, not just with a good run...!

03-22-2010, 10:37 PM	#1
jaimico Drives: yaris advance Join Date: Jan 2009 Location: pty Posts: 62	Low rpms with a new battery Yesterday my 2008 yaris sedan battery just past the way, and I replaced it with a bigger model (from 350 to 500 cca), since I could not find the same size or capacity as the original. To my surprice, after replacing the battery, I started the car right away, but the rpms just when to the minimum, like 300-500 at idle (normally are around 700), it was like having a 3 cilinder engine, let it run for a while, but did not change, so i took it for a good run, and still the rpms where dropping at idle, and suddenly it just came back to normal. Today i had my 50K maintenance, and when I came home disconected the battery to adjust the supports, and when I started the car again , the same problem again, but this time at a smaller rate (the rpms where around 500 know). So, is it something with the car computer the need to adjust after a while, or what??, since the alternator was chargin normally.

04-05-2010, 08:44 AM	#5
jaaf Drives: Belta 2006 Sedan Join Date: Jul 2009 Location: Pakistan Posts: 4	I'm facing the same problem with my 2006 yaris sedan 1.0 after changing battery terminals.. if a good run will solve my problem too? __________________

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03-23-2010, 03:02 AM	#2
yaris-me Learn to Relax Drives: 2007, Meteorite, LB Join Date: Dec 2008 Location: Anaheim, CA Posts: 2,070	The ECU is adaptive and it will adapt to your driving style. When you disconnect the battery the ECU will reset to default. After running a while it will adapt again.

03-23-2010, 10:40 AM	#3
Yaris Hilton Half a Bubble Off Plumb Drives: 2009 Yaris Sedan Join Date: Mar 2009 Location: Bristol, Tennessee, USA Posts: 1,593	Also, if the new battery wasn't fully charged, drawing heavy charging current could drag the idle speed down. I'd think the ECU would regulate the idle speed, but people notice fluctuations when the AC compressor kicks in and adds load...

03-23-2010, 10:41 AM	#4
jaimico Drives: yaris advance Join Date: Jan 2009 Location: pty Posts: 62	Well that one is new, today I came back to normal, thanks for the tip.

04-05-2010, 01:40 PM	#6
TheSilkySmooth Drives: 08 3DR 5M Bayou Blue; 09 Fos Join Date: Oct 2008 Location: New Hampshire Posts: 622	Its just the ecu relearn. thats all. No Problem - unless it NEVER comes back.

04-08-2010, 09:35 AM	#8
kazama82 Drives: VIOS Join Date: Nov 2009 Location: Malaysia Posts: 42	few days..

04-08-2010, 06:17 PM	#9
jaimico Drives: yaris advance Join Date: Jan 2009 Location: pty Posts: 62	the more you use the car it will go away sooner, not just with a good run...!