Battery not charging (but battery light not on)

[mcfee03]

Originally Posted by Crowz

I have a feeling you may do more harm than good the way things are going.

I appreciate what you're saying, and I'll keep from trying things before asking here. Got a little ahead of myself. I am learning a lot and would ideally like to continue.

For example. I've got the positive terminal in the engine area as well. Is there a specific order the new battery and leads should be connected in? Is the voltage I'm getting normal (11.8v then 13.6v at running)?

How can I clear the code and thus the trans fail-safe?

[Crowz]

Originally Posted by mcfee03

I appreciate what you're saying, and I'll keep from trying things before asking here. Got a little ahead of myself. I am learning a lot and would ideally like to continue.

For example. I've got the positive terminal in the engine area as well. Is there a specific order the new battery and leads should be connected in? Is the voltage I'm getting normal (11.8v then 13.6v at running)?

I normally hook the positive up first when installing and disconnect the negative first when removing the cables.

It actually doesn't matter which you do first no matter what anyone tells you as far as the car and battery are concerned.

The reason to connect the positive first is in case you touch the body of the car while tightening the positive cable to the battery with a wrench. If the wrench touches with body with the negative not connected then nothing happens. If you connect the negative first and then touch the body while connected the positive cable you can cause a very bad and potentially explosive short.

The same goes for disconnecting the battery. You disconnect the negative first since touching the body of the car while removing the negative cable is harmless and once its removed if you touch the body while removing the positive at that point nothing happens.

[upallnight]

Originally Posted by mcfee03

I appreciate what you're saying, and I'll keep from trying things before asking here. Got a little ahead of myself. I am learning a lot and would ideally like to continue.

For example. I've got the positive terminal in the engine area as well. Is there a specific order the new battery and leads should be connected in? Is the voltage I'm getting normal (11.8v then 13.6v at running)?

How can I clear the code and thus the trans fail-safe?

That's a red flag in my book when people mention that they figure out there's a positive terminal in the car. My neighbor hooked up the battery incorrectly to his Rolls Royce (Yeah I know we live in a wealthy part of town) and blew the shunt module for the car. Nothing work, not even the headlight. Did some trouble shooting for him and told him that the shunt module was blown. He ended up selling the Rolls at a big lost.

Did you hook up the battery backward? If you did you probably blew out some modules or at the very least some fuses.

[blakamin]

A battery nap *might* help get out of failsafe mode, but it wont reset any codes.
Disconnect battery for 30 mins. Then try again.
This works in earlier models (E38 etc) but I'm not sure about the E53.


If it doesn't work, stop doing random things you find on the net and ask here. Your car has more than 1 computer (try about 20), and BS like holding pedals down and counting to 10 while you do the twist will not do anything to any of them.

[mcfee03]

Originally Posted by blakamin

A battery nap *might* help get out of failsafe mode, but it wont reset any codes.
Disconnect battery for 30 mins. Then try again.

No luck with that.

I feel this is all related to electricity.

• My voltage at ignition position 1 & 2 is 11.9v.
• At running (idle) it's 13.6v (shows that read for 5 seconds, the the Trans. Failsafe comes on).

I just tried to plug a cigarette USB port into the socket- it sparked and stopped working (the USB). I tried another USB (very briefly) and it made a whining noise, so I unplugged it immediately...

Maybe unrelated, but i hear this clicking/ticking sound from the passengers side (in Australia, so LHD). Here is a video of how it sounds


Remember, I'm very new- so may had missed something basic.

[blakamin]

Oh, and if you're paranoid, put down some windows first.

[Crowz]

As for voltage if the battery is fully charged and "good" then it shouldn't drop below 12.2 volts with the interior lights on. Resting voltage (no lights or anything else on) should be 12.5 to 12.6 volts on a fully charged battery.

13.8 running is normal. 13.6 usually means a weak battery being charged and will climb up to 13.8 or higher once it charges up. If the battery isn't bad.

[mcfee03]

Originally Posted by Crowz

if the battery is fully charged and "good" then it shouldn't drop below 12.2V

I'm only getting 11.9v. Could this be the cause of my trans fail-safe prog error? I bought this battery today- maybe they sold me a bad battery?

Would using jumper cables to start instead be worth trying?

EDIT: My odb tool can apparently clear codes. Will try

[Crowz]

The last part of your question on clearing the codes requires a scan tool that can clear codes. If you don't see that in the list on the scanner when its hooked up to the car then it probably is a real cheap one that doesn't have that ability.

If your going to do your own diagnostic work on a bmw then you are going to HAVE to buy a decent scan tool.

In the united states that means spending at least $100 in Australia that may be a bit higher. But its money well spent and its pretty much a requirement.

[mcfee03]

I cleared the codes with my ignition running. The code disappeared for a few seconds, then came back.

I then cleared in ignition position 2 and while driving- the trans fail-safe comes back.

When I unplug the MAF sensor while the engine is running, the engine keeps running (I believe it should STOP running if the MAF works)? Could my new battery have killed the sensor and other sensors?

What's next to try?

Topic getting very long- thought I'd post the continuation here- https://xoutpost.com/bmw-sav-forums/...ml#post1118144