Changing Battery:Will I loose engine codes?

Hi Everybody,

The battery in my 2000 VW Golf TDI needs to be changed (it is the original battery). I have heard a lot of talk about the engine codes that will be lost if there is any break in power supply to the car, and that I will need to go back to the dealer and get charged $75 to have the computers reset.

I called 3 different dealers and got 3 different answers. My owners manual just mentions the MFI display, radio, and windows needing to be reset (I have roll-up windows and no MFI, so I just have the radio), and my service manual says that I "may" have some drivability problems and need to have the computer reset. One of the dealers said that because my car was a Diesel that I might not have any problems.

I would really like a straight answer on whether I need to do some elaborate procedures to maintain power to my car while changing the battery, and if so, what is the best way to do it? Also, if I did loose programming, I would assume that they would default back to the initial factory settings, which would seem to be fine.

Also, what is the best type of battery to use? I have heard that the Type 48 battery is the proper replacement.

I would just greatly appreciate a straight answer from the Forum which seems to be the only people that know the actual answers for these TDI cars in particular! I can't believe how the dealers can't give me a straight answer on something as simple as this!

Thanks again,

- Brock

The battery in my 2000 VW Golf TDI needs to be changed (it is the original battery). I have heard a lot of talk about the engine codes that will be lost if there is any break in power supply to the car, and that I will need to go back to the dealer and get charged $75 to have the computers reset.

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Those boyz be smokin' serious crack. There's nothing to be concerned about. Yeah, you might have to reset the clock + radio and you could lose the tripmeter reading. The ECu will be fine. There is nothing to reset.

The actual code for your battery (2000MY) is a 94R(-675). It is not a BCI Group 48.

BCI chart:

Go to any auto parts store and for around $10, you can get a computer memory holder. It uses a 9 volt battery. It works fine, no prblems.

I've had my battery out for ~20 minuts and the only thing I lost was the clock and trip. Didn't have to 'Un-Safe' the radio, didn't loose my presets.

YMMV

-Jason

I changed mine out (used a 94R battery, from AutoZone/DuraLast), on a 2002 Jetta TDI wagon, I had it disconnected for maybe 20-25 minutes. Whenever I disconnect the battery (or when it dipped voltage when I was trying to crank the engine), I lose the adaptation values, that's all. I've never had a problem associated with the stereo or alarm. Because of the adaptation resetting, I lose the auto-up auto-down of the windows, and the "selective unlocking" (meaning when you press unlock on the remote twice, all 4 doors unlock). But those settings all re-learn themselves once you put the windows all the way down and up (using the key turned in the door, I think). The warning disclaimer always states that you might have driveability / engine operation problems until it's re-adapted, but mine never suffered. I think the throttle position sensing is part of that too. The designers must anticipate that the battery will occasionally fail; Larry.

BTW the service book states that after changing the battery, you're supposed to turn on the ignition key for something like 10 seconds (without cranking), then turn it to the "off" position for 5 or 10 more seconds. Larry;

I've disconnected my 2001 Golf's battery many times. The only thing I needed to do was reset the clock, and I think I lost the trip odometer reading.

Just changed mine out on my y2k jetta... no problems reset radio presets clock and odometer.
Clean the grounds under the bottom of the battery box while you have the battery out.

I also need to replace the battery for my 2001 TDI..

So to order one from a autoparts place... all I need to ask for is a: 94R(-675) Is their any additional identification or battery type information to ensure I purchase the correct size and type?

No, that ought to be a good one -- I don't see how you could have a mismatch if it's really a "94R"; Larry.

... all I need to ask for is a: 94R(-675) Is their any additional identification or battery type information ...

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do you mean the adaptation settings for the IQ and such get resetted too when the battery is disconnected?

I changed mine out (used a 94R battery, from AutoZone/DuraLast), on a 2002 Jetta TDI wagon, I had it disconnected for maybe 20-25 minutes. Whenever I disconnect the battery (or when it dipped voltage when I was trying to crank the engine), I lose the adaptation values, that's all. I've never had a problem associated with the stereo or alarm. Because of the adaptation resetting, I lose the auto-up auto-down of the windows, and the "selective unlocking" (meaning when you press unlock on the remote twice, all 4 doors unlock). But those settings all re-learn themselves once you put the windows all the way down and up (using the key turned in the door, I think). The warning disclaimer always states that you might have driveability / engine operation problems until it's re-adapted, but mine never suffered. I think the throttle position sensing is part of that too. The designers must anticipate that the battery will occasionally fail; Larry.

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As usual, you were all exactly right! I changed my battery without any problems or drivability problems. Thanks again!

- Brock

According to the Bentley instructions, yeah. I don't know about IQ specifically, but they do advise about driveability and performance degradation, until the adaptations have been re-acquired. I didn't experience any problems, but I have noticed the obvious effects every time my battery is out of the circuit, namely that the auto-window-up/down is cleared and the selective unlocking (4 doors) goes away for a bit. I've never seen any effect on my stereo (premium 5 double DIN, 2002 vehicle), i.e. no troubles or anything.

Funny thing now (after replacing my battery) I've noticed that the alarm will arm (horn chirps once) while the passenger door is open, my car's never done that before. Normally, if locked via the remote while a door (or hood or rear) is open, it will arm/chirp once the last door shuts. I'll have to look that up to see whether I have to fix something; Larry.

do you mean the adaptation settings for the IQ and such get resetted too when the battery is disconnected?

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Never mind that last note, turns out it has nothing at all to do with the battery/memory stuff ... my sensor switches on the passenger side are going nutty i.e. sticky. Also found an extensive post concerning locking/microswitches/alarm on vwvortex; Larry.

Funny thing now (after replacing my battery) I've noticed that the alarm will arm (horn chirps once) while the passenger door is open, my car's never done that before. Normally, if locked via the remote while a door (or hood or rear) is open, it will arm/chirp once the last door shuts. I'll have to look that up to see whether I have to fix something;

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I just changed my battery and when I hooked it all back up, only the clock and the trip odometer had been reset. The radio said 'SAFE' when I powered it up, but it worked just fine after that.

I'm still confused, because I want to keep my iq at 7.8 and the egr at minimum 33768... will removing the battery require me resetting these adaptations in vag com?

I ask because im not sure if by adaptation they mean internal ecu stuff, or the things that we can modify via vag com.

I just used this info to feel ok about replacing my battery. I got in after disconnecting the battery for about 10 minutes max and my security system has made it impossible to start the car. I was under the impression that the security system wouldn't disable the car from simply replacing the battery. I had also called the vw dealer and the service department said there was no problems replacing a battery. So anyone want to venture a guess at why this happened and what do I do now?

Bought one of these at Wally World couple of years ago under $2 and it will allow a battery change as long as radio & CD player, parking lights, are not on while doing change out.

In September of 2003 at 84k, I changed belts, cleaned intercooler, cleaned snow screen (behind and below battery), etc. During the process, I had the battery out for better than 5 or 6 hours.

Then at 116k this past June, I had to change left head light bulb. So, while I was under the hood, I checked and cleaned the snow screen again, which requires removing the battery.

Each time, I only lost trip meter and clock settings.... no big deal.

I am at 133k now and no problems.

So, while I was under the hood, I checked and cleaned the snow screen again, which requires removing the battery.

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You shouln't have to remove the battery. Just the air filter box. Take one 10mm nut off the side of the car and the snorkel/snow screen should just slip right out past the battery. If you've got a fast internet connection (or patience), check out MOGolf's how-to video:
http://www.cincitdi.com/richc/

Yep, well, you are right. I did see that it wasn't necessary to remove the battery. But, I had the battery out to change the headlight bulb. And, the first time, I actually took the entire front off the car to remove the right head light to get the turbo piping and intercooler off to clean them.

Thanks

Al, sorry I don't know enough about the programming and memory and the security system to explain what happened. Does anyone know whether it matters, after reconnecting the 12V, where to insert the key (door or ignition); any particular sequence that would cause problems? (I think I recall the Bentley manual saying to insert the key, turn ignition on, then off, after reconnecting battery ... stereo and other accessories off I believe) Larry.

So high guys, from what I can see I see that the answer really hasn't been given. The question relates to codes and battery removal. I am in such a predicament I have remove my battery and in the m i l came on and since I wasn't going to fix it directly I parked it for several weeks months and went to another vehicle. I have since moved battery to a charging station to maintain it not thinking about the codes or anything else just going about my life and not worrying about the car. So the question again on this old thread can the codes disappear when the battery is removed?

Best regards to all,

Jharl

On an '04, No.

Thanks that answers it. I would think that would be the case for most model years.

Jharl