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Discussion Starter · #1 ·
I know they don't recommend a memory saver for when you disconnect the battery. I was wondering about this particular one. Just plug it into a jumper box and then into you OBDII port. Any opinions or comments?

 

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So... It plugs into your OBD port, and plugs into the cigarette lighter of another car? How odd. I'll admit I was quite concerned about the "lost settings" issue, so I did a lot of research on it. The general problem seems to be that most of these gizmos use a 9V battery, which is insufficient to keep the settings intact. First time I removed my battery, I went to a great deal of trouble to rig a 12V source, like this device. I did indeed keep my settings without problems.

HOWEVER, next time around, I didn't use a voltage source, and found the few settings lost were so trivial they weren't worth preserving - specifically, the trip odometer reading and the window auto-up setting. That's it. I wouldn't even bother. I don't know why the shop manual makes such a big fuss, stating the car may become undrivable. That's never happened to anyone, all the years I've been on this forum.
 

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I wonder if the logic portion of the digital controllers (car computers) operates on +3.3vdc or +5vdc like many personal computer chips do. If that's the case, a 9vdc battery regulated down to 3.3 or 5vdc would provide sufficient voltage as long as you didn't ask it to deliver much amperage. If opening a door caused the interior lighting to draw from the Memory Saver source, the battery current output would max out and voltage would plummet.
 

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Discussion Starter · #5 ·
My theory on why they don't want you to use them is actually quit simple. You plug the saver into your lighter, disconnect the battery, drop the positive wire onto the frame and WHAMO, instant short! I don't know if that's way but it sounds good in my head. And yes, some times I do listen to the voices.

If you lose the window up feature is there a way to get it back without a vag-com?
Also what about the radio security code? Is that a problem? If so how do I get it before I disconnect?
 

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Re-learning the windows couldn't be simpler. Hold the window switches to lower the windows all the way. Then raise them all the way. I forget if you need to do that once or twice, but that's all there is to it.

The four digit radio code should be documented somewhere. It could be with the owners manual literature. It might be written on a sticker in the spare tire well. The dealer can usually get the code for you. Sometimes they want to charge for that service. Some radios recognize the car as the one that it belongs in and unlocks itself from SAFE mode all by itself.

The only real reason to worry about a battery disconnect is if the throttle body loses its calibration and needs to have a Throttle Body Adaption run on it to get it re-calibrated. Everything else is simple to re-learn or re-program.
 

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Discussion Starter · #7 ·
I read some of the post regarding TBA. Key in ignition, wait and so on. Does this work 100% of the time and is it accurate? Or just enough to get by. I don't have a vag-com and I cant afford to take it to someone who does. Actually I just started a new thread on the vag-com system trying to learn a few things about it. Seems to be the tool to have.
 

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I've disconnected my battery many times and never had any need to do a TBA after reconnecting the battery.
You know most of the time when step 1 in a VW repair is "disconnect the the battery" it's just so no one jumps in and tries to start the car.
Unless of course you are working on something in the electrical system.

The radio code is not on the tire well sticker. It only appears on a stereo card in the owners manual with the serial # of the radio. But, I think Steve is correct that most of the cars if the code has ever been entered in the past the radio then knows the car. Otherwise, the dealer would need to give you the code.

Had a Toyota years ago that I had to enter the darn code just about anytime you popped the hood.
 

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Discussion Starter · #10 ·
Found the radio code. It wasn't in the spare tire compartment but it was in the book on a card that said tear out and put in a safe place which the PO did. Fortunately he remember to include it with all the service records. I would have also torn it out and put it in a safe place. Unfortunately I can never remember where that safe place is.:hmmm: Don't laugh folks. I sure I'm not the only one.
 

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I read some of the post regarding TBA. Key in ignition, wait and so on. Does this work 100% of the time and is it accurate? Or just enough to get by. I don't have a vag-com and I cant afford to take it to someone who does. Actually I just started a new thread on the vag-com system trying to learn a few things about it. Seems to be the tool to have.
No it doesn't. I've had my 99 Passat from new. It's absolutely impossible to start after loosing battery power. There are several techniques published to do an adaptation, none of them work. Only the licensed vagcom TBA works. All the other stuff is BS.
 

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Discussion Starter · #12 ·
How strange. Some cars have problems some don't. Some have major problems some have little problems. I think I'm going to air on the side of caution. I just ordered a vag-com usb cable. Thanks every one for your feedback.
 

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Just a note: Not that I doubt javis20's car acts that way, BUT - it's the first person I've heard report that. Certainly my 2000 and 2004 showed no such inclination. Any other 1999 owners able to drive after disconnecting the battery?
 

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Discussion Starter · #14 ·
I've read several post were people had problems and several were people had no problems. I do wonder if it's possible year or engine or maybe even platform related. Or maybe a combination of such things. You would think disconnecting a battery no matter what its on would all have the same results.
 

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Actually it just happen again last month. I told my wife to stop by Autozone and have them throw in a new battery. She requested them to use the memory saver but they poo poo'ed the whole idea. So as typical of wives, she believed the Autozone guy rather than me. Cut to the chase, I had to leave work and drive my laptop to Autozone to do a TBA to get the car started. And I know I'm not the only one, because I've helped several people with this same problem. From my experience, the cars affected are usually the 98 thru 2000. Not sure if the problem really has to do with the cars year of manufacture of if it's a function to the throttle bodies default position being out of range initially. I lean toward the latter.
 

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No it doesn't. I've had my 99 Passat from new. It's absolutely impossible to start after loosing battery power. There are several techniques published to do an adaptation, none of them work. Only the licensed vagcom TBA works. All the other stuff is BS.
This is an odd post. I've had my April '99 manufactured B5 since June 9, 1999 (>15 yrs), replaced the battery four times, and had the ground cable removed for countless maintenance events. I didn't locate a battery saver until about 2003 or so; after that I used it to save settings.

I have never needed to do a throttle body realign in order to start my car after the battery has been disconnected. (Your throttle body has issues, Id' say).

:beer:
 

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I have never needed to do a throttle body realign in order to start my car after the battery has been disconnected. (Your throttle body has issues, Id' say).

:beer:
I've always suspected that there are some throttle body's whose default position is not conclusive to starting without a full alignment. Otherwise my throttle body works just fine.
 

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I have never needed to do a throttle body realign in order to start my car after the battery has been disconnected. (Your throttle body has issues, Id' say).

:beer:
I've always suspected that there are some throttle body's whose default position is not conclusive to starting without a full alignment. Otherwise my throttle body works just fine.
 

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When I put my 99 back together, I had to do a TBA. No biggie with VCDS. When I disconnected the battery to reroute the alternator cable, I had to do a TBA again after reconnecting the battery.

Most manuals I've read always say "Disconnect the negative battery cable." So plugging in a memory saver wouldn't short anything out, as long as the negative cable doesn't touch the positive cable.

Since I have VCDS, I'm just going to disconnect the battery and be done with it when I pull the battery and tray to clean from underneath it.
 

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The only times that I have heard of a B5/B5.5 TBA problem is when the throttle body has been removed and cleaned or replaced,
or the ignition has been switched on with the throttle body disconnected. In all these cases the engine would start and the car could be driven with minor if any problems.

It is OK to replace a battery with a memory saver connected, but in my opinion of little if any benefit.
Do NOT use a memory saver while doing any other electrical work on a car.
 
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