[PabloCruise]

Hello Friends!

Last Tuesday my e46 threw a p1632 Throttle Adaptation code at my wife and went limp.
I went and brought her truck to her, cleared the code and drove it home.
It sat until today when I went to wash it. My key remote function would not unlock the door - uh oh!
I unlocked the trunk and checked battery voltage - it was at 5 volts.

I did some searching and found this: How to methodically find the battery drain in our E46–and fit an Opt As everyone in the comments notes - Metallica! The page is useful, but turns into an ad for Optima batteries. TL;DR they found the fuel door actuator was jammed, and then that the battery was bad.

I will let the battery charge overnight and start this process.

Any other ideas?

 

[PabloCruise]

PS: vehicle in question is an '02 325i.

 

[PabloCruise]

New battery in Dec (30th) of 2020.

 

[markusmarkus]

First, 5VDC at the battery tells me the battery is bad. I’d take it back to wherever you bought it and get a replacement. Next, after installing the new battery I’d drive the car for an hour or so to charge the battery. Huh? Batteries sit in the shelf at the parts store sometimes for months. They lose charge when sitting. Once the battery is properly charged id check the voltage at the jumper post located under the red plastic cover under the hood. Use the engine as the ground. Check the voltage with just the hood opened. Then check the voltage when the ignition switch is in the run position but with the engine off. Then check it with the engine idling and then with the engine revving at 2000 rpm. Report back your findings.

I’d check the main engine ground strap that’s located on the exhaust side of the engine, at the bottom front of the engine.

 

[PabloCruise]

I hear you brother on charging the battery. Whenever I get a new one, I always put it on the trickle charger to fully charge the battery to put it into service.

My thoughts were that 5 volts is sign of a parasitic drain, but I guess it sure could be a bad battery! A bad battery will be the source of all kinds of trouble. It is w/in warranty, so I will swap them out.

 

[MrMCar]

Agree with the above. Any "new" battery should receive a minor charge before installing into any car.

It remains a bit ambiguous if you have further issues. First I'd unlock the instrument cluster menu and scroll over to test #9, from there you can see the car's system voltage and observe (hopefully) an alternator that's charging properly.

Normally a stuck lock actuator doesn't create a patristic draw.

 

[RRRM8E]

I'd do the drain test with ammeter first.

 

[beechbmw]

This post, along with the associated video, may help after you get a fully charged battery AND ensure your charging system is OK.

You mentioned that battery is less than a year old and you know you bought a quality battery then we can assume the battery is not the problem From there it will take some troubleshooting on your problem to find the parasitic drain. Common failures are the aux fan module or fan, a aftermarket stereo system add on or the OEM radio or navigation system. You need to set the car up for sleep mode with trunk and passenger door open and in sleep mode. Then start looking for draw with you volt meter. The car should sleep at around 38 milliamps. Anymore and you will slowly drain the battery. Here is a video for reference.

 

[PabloCruise]

Thank you all, as always, I appreciate the help.
It turns out that my multi-meter does not have an ammeter built in.
Do y'all have a recommendation for a DC ammeter that is a preferred/favorite?
I am going to try to scare one up locally if I can borrow, but it is probably a good thing to own...

 

[RRRM8E]

Just find a multimeter with 10A function.

 

[Sapote]

It turns out that my multi-meter does not have an ammeter built in.

This is a rare one. Product part number?

 

[PabloCruise]

This is a rare one. Product part number?

I don't know, I will check!

 

[PabloCruise]

I did find this, which just looks at voltage at each fuse:

 

[PabloCruise]

First, 5VDC at the battery tells me the battery is bad. I’d take it back to wherever you bought it and get a replacement. Next, after installing the new battery I’d drive the car for an hour or so to charge the battery. Huh? Batteries sit in the shelf at the parts store sometimes for months. They lose charge when sitting. Once the battery is properly charged id check the voltage at the jumper post located under the red plastic cover under the hood. Use the engine as the ground. Check the voltage with just the hood opened. Then check the voltage when the ignition switch is in the run position but with the engine off. Then check it with the engine idling and then with the engine revving at 2000 rpm. Report back your findings.

I’d check the main engine ground strap that’s located on the exhaust side of the engine, at the bottom front of the engine.

Some progress - exchanged the battery last night and drove for a while. Then parked the car and put the trickle charger on.
Battery after charging is 13 volts. Voltage under the hood while running = 14.21v. Voltage at the battery while running = 14.13v
I still need to check voltage w/ key ON, but engine OFF.

 

[RRRM8E]

Question is whether voltage holds overnight.

 

[PabloCruise]

Question is whether voltage holds overnight.

12.7v this AM.

 

[Lynas]

12.7v this AM.

That's normal.

I think Chris Fix did a video on parasitic draw

(EDIT: No he didn't it was the one posted above)

 

[Sapote]

12.7v this AM.

So it is not a current draining issue, but just a bad battery that you had.

 

[PabloCruise]

This is a rare one. Product part number?

Gardner-Bender GDT-3190

Gardner Bender GDT-3190 Digital Multimeter, 4 Function, 16 Range, Tests AC/DC Voltage, Resistance, and Battery, Manual Ranging, Auto-Off

When you're ready to add a multi-meter to your toolbox this unit is an excellent choice. Designed to work on most household appliances and equipped with an easy-to-read 3.5 inch digital display this Gardner Bender multimeter features rubber housing to promote a steadfast comfortable grip...

www.gardnerbender.com

 

[RRRM8E]

I would check for parasitic draw. How else did it get to just 5V?