Putting in a new battery, does the car have to "relearn" anything (idle, A/F ratio)?

[Coconut]

Putting in a new battery, does the car have to "relearn" anything (idle, A/F ratio)?

After you put in a new battery does the NSX require a certain amount of time idling or driving around to "relearn" anything?

On my previous cars, I've been told to let it idle for 5-10 minutes then drive it around for 30 minutes so the ECU "relearns" the correct setting.s

 

[sylcurt]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

When I did my stereo installation last winter (18 months ago), I had battery disconnected for several weeks while I worked on it in evenings....when done hooked it up, and car ran exactly the same after as before....

 

[davidf]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

It will relearn as you drive, though you'll feel no difference.

 

[PHOEN$X]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

I didn't do anything special after disconnecting/reconnecting the battery (for installing battery tenders) on my NSXs.

 

[docjohn]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

from what i recall and have experienced with my obd-2 ecu it does relearn the idle and also needs to be all warm and fuzzy with the o-2 sensors.

 

[bngl3rt]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

I have been told to drive over 100 miles after reconnecting the battery before taking the vehicle to get smogged, precisely so that the OBD2 system can relearn the O2 sensors and etc.

 

[TANTO]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

I have a switch on my battery and turn this switch off instead of using a tender. My car then is ALWAYS in a learn mode. I"m wondering if performance is affected.

 

[PHOEN$X]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

I have a switch on my battery and turn this switch off instead of using a tender. My car then is ALWAYS in a learn mode. I"m wondering if performance is affected.

Why not just install a tender? It's not that expensive and I'd hate having to reset the clock, radio stations, etc. every time I wanted to drive the car.

 

[TANTO]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

Why not just install a tender? It's not that expensive and I'd hate having to reset the clock, radio stations, etc. every time I wanted to drive the car.

I have an Odessy 925 and while many have said they have no problem using a tender on it, the Odessy folks say it sulfate their battery. Ironically Odessy's own charger messes up unless one bat terminal is disconnected. With my scheme I never need to charge as the Odessy will hold it's charge for a whole winter. And i don't want the weight of an onboard. Yes i am a weight fanatic. I don't have a working radio.

 

[clean_green]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

I have a switch on my battery and turn this switch off instead of using a tender. My car then is ALWAYS in a learn mode. I"m wondering if performance is affected.

Yes, your car is always in learning mode and performance is affected. Depending on your mods, it may perform better since the OBDII isn't adapting to them. BUT, as I learned on my Prelude, this wreaks havoc on your emissions system. I had to replace O2 sensors and the cat. Fortunately I managed to get this done under an extended emissions warranty the Honda had to offer.

 

[nikey22]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

Steps to take:

Let the car idle for roughly 15 minutes, or until the car is idling smooth at lower rpm’s. Important: Do not interfere with the process, do not give it gas. You will hear the car increase and decrease rpm while it is conducting the test, this is normal.

Turn the ignition off. Then immediately turn the ignition back on after you have gone to full off. This will store the new settings your ecu has made.

Do this everytime you disconnect the battery, essentially, you are resetting the ECU.

 

[DDozier]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

After you put in a new battery does the NSX require a certain amount of time idling or driving around to "relearn" anything?

On my previous cars, I've been told to let it idle for 5-10 minutes then drive it around for 30 minutes so the ECU "relearns" the correct setting.s

Both OBDi and OBDii cars will relearn the fuel trims after the ECU has been reset. This process happens very fast and will be completed durring your first drive cycle. The OBDii emmision test may or may not be complete in the first drive cycle so you may have to drive the car a few times before you go for an emmisions test after the battery is replaced. You can avoid the reset if you want by hooking another battery or battery charger to the jump terminals in the engine bay fuse box. This will keep the entire 12v system up while you replace your battery. Use caution with the possitive lead of the battery as it will still have power and should not be shorted to any ground on the car.

Resetting the ECU is not an issue, and can be done with no ill effect to the NSX, so if you do not mind reprogramming your radio stations then replacing the battery without this extra step is fine. On more modern cars this is the preferred method to replace batteries in cars and trucks. Many new cars require seat and window relearns if power is lost completely so this method can save you time reading the manual to figure out the relearns or a trip to the dealer if you do not want to figure it out.

Dave

 

[TANTO]

Re: Putting in a new battery, does the car have to "relearn" anything (idle, A/F rati

My 92 which i believe is OBDi has no cats and of course only one O2 sensor. I have been assuming there is no learn program on my car. But i'm not sure i've ever proved this out. Frankly i hate learning programs. Was looking at used BMW X3's lately. Their learning program totally messed up their transmission which works well ONLY in learn mode. Totally ruined this vehicle IMO. Bought a RDX which i'm very happy with, but i sort of wanted to stray a bit! But that tranny was not acceptable period!

 

[MC36]

I have had this issue lately where my car has been on a battery tender but the car still will not start. I think that there is an issue with the tender. I took it to have a state inspection today and the tech said that I need to drive it a while to have it reset. I am looking on prime to find out how far. Does anyone know? Is is 10 miles, 20, or 100? I need to find out one why my battery tender does not work now and two how long do I have to drive it to reset the drive cycle. Any suggestions?

 

[DDozier]

This is for a Civic but it should be the same for almost any OBDii car.

http://wiki.answers.com/Q/How_do_you_reset_the_drive_cycle_on_the_OBDII_computer_on_a_Honda_civic

 

[MC36]

THank you that is just what I needed. This seems like a bit much but I'm willing to try it.

Thanks,