2012 Passat TDI battery replacement procedure

I have searched this forum as well as the internet and could not find a answer to this question. Is there anything special about replacing the battery on this car yourself? The last 2 times I started the car cold it turned over slow but it started. I'm not going to mess around with the battery, I'm just going to replace it. Any special advice?

From what I gather different cars will act somewhat differently. Unless you maintain a hold voltage you'll usually suffer the loss of some presets. Most will not be an issue and most will correct by themselves after a short drive.

Remove the negative terminal first when replacing the battery and replace it last. Really not much more than that and all should go smoothly.

So it sounds like it is a run of the mill battery replacement job. Thanks Nord.

Nothing fancy. Unhook battery and replace.

You'll have several warning lights when you start the car again. A quick drive will clear them.

What about the radio security code? Will it ask for it, or does that only happen if the radio is physically removed?

atc98002 said:

What about the radio security code? Will it ask for it, or does that only happen if the radio is physically removed?

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I have removed the batteries on almost all of my VW's at some point or another, and have not had any issues with the radio code (ie, it never asks for it).
Only time I've had to input the code is when I swapped units between vehicles.

atc98002 said:

What about the radio security code? Will it ask for it, or does that only happen if the radio is physically removed?

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It will not prompt for a code during a routine battery replacement.

Good to know. Thanks!

That job was a piece of cake. A couple of dash stayed on for a few seconds and I had to reset the clock. That was it.

Battery

What battery mfg. did you use? What size ect. I hear that VW takes a particular type size? Is this true? I am thinking of doing a preemptive replacement.

Thanks, Gary

goldgary said:

What battery mfg. did you use? What size ect. I hear that VW takes a particular type size? Is this true? I am thinking of doing a preemptive replacement.

Thanks, Gary

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I got a Duralast Platinum size H6-AGM. You will need a 10mm socket for the battery cables and a 13mm for the bolt that holds the battery clamp on. I would also suggest a 15" extension for the 13mm sockets. Total replacement time was about 10 minutes (yeah I'm slow).

goldgary said:

What battery mfg. did you use? What size ect. I hear that VW takes a particular type size? Is this true? I am thinking of doing a preemptive replacement.
Thanks, Gary

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I believe that it's a Group 47 battery.

Any H6 battery. Got mine at Walmart. H6 battery, 5 yr. warranty. $117.

VCDS info says you have to do the steering calibration after a battery disconnect. VW hadn't heard of EEPROMs, apparently. I will bridge it with a plug-in supply, reliably connected perhaps at the fusebox, next time I have to disconnect a VW battery.

verylongdrive said:

VCDS info says you have to do the steering calibration after a battery disconnect. VW hadn't heard of EEPROMs, apparently. I will bridge it with a plug-in supply, reliably connected perhaps at the fusebox, next time I have to disconnect a VW battery.

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Replaced various batteries on VWs with electronic power steering. Got a steering steering warning light and I have VCDS and never used it to clear it. The ABS, steering, tire pressure, and traction control lights self-clear once you start driving the car. No residual pending codes or faults. Maybe I'm doing it wrong but the cars think I'm doing it right with no residual effects on function.

I seriously doubt dealer techs recalibrate the steering on every car with the dealer tool every time they remove a battery or de-energize the system during service.

verylongdrive said:

VCDS info says you have to do the steering calibration after a battery disconnect. VW hadn't heard of EEPROMs, apparently. I will bridge it with a plug-in supply, reliably connected perhaps at the fusebox, next time I have to disconnect a VW battery.

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Not necessarily. Disconnecting the battery does about the same thing as doing the power steering reset through VCDS. The procedure has you turn the wheel lock to lock a few times and such but it's not really necessary. The fact is that system will learn all it needs under normal driving. Don't over think this. When you disconnect your battery you'll have traction control and steering faults on the dash. Just drive it and make a couple left and right turns and the faults will disappear. The car will use the 4 wheel speed sensors while driving to determine what should be center on the steering wheel. When all 4 wheels are going the same speed the car knows it's not turning. It then looks at the current steering wheel angle and says, "Okay that must be center."

Don't bother trying to power the fuel box or ECM while the battery is disconnected. There just isn't a point in bothering with all that. No, if you're looking for parasitic draw you'll want to leave the battery circuit powered while disconnecting the battery to install an ammeter in series. This is to keep the modules powered so that they don't all awake when they shouldn't showing a false draw issue. To do this you can put a battery booster on the pos and neg terminal clamps and remove the terminals from the battery. When the ammeter or DVOM is put in series with the circuit you disconnect the battery booster.

fastyz400 said:

Any H6 battery. Got mine at Walmart. H6 battery, 5 yr. warranty. $117.

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There is no vent to install on the car, is there? I'm also about to install an H6 tonight.

Update: I just did this last night. No vent tubes to hook up