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I'm fighting a parasitic battery drain on my car (again)
I went through all the usual troubleshooting steps, but my problem is slightly different: one module randomly turns on and off over time.
Below you see a chart of battery draw over ~18 hours.
As you can see the draw is not constant
I did several of these samples and one thing is always the same:
When it's dark outside I have an average draw of less than 20 mA (which it should be)
During the day it randomly jumps to 3.3 - 3.4 A for 20 - 30 seconds (it's always the same draw, so I think it must be the same module)
What module could be triggered to turn on only by daylight?
One more hint: sometimes I see the red LEDs on the two temperature adjusters blinking when the car is parked.
I haven't tried a W221, but Xentry can display network activity on the CAN/s. Depending on the chassis, the level of information varies... but it useful nothing the less to narrow down what module is waking up.
I am looking for some ideas how to find this parasitic drain
What I know that many times in a 24h period *something* in the car gets activated and then draws 3.3 - 3.4 Amp for 20-40 seconds.
Naturally this is very hard to troubleshoot
I tried some reverse engineering: I tested the current across each fuse using an "AmpHound" to see if there is anything that draws this kind of current.
And it turns out that the fuel pump draws exactly this current.
So I pulled the fuse for the fuel pump and did a long time test again, unfortunately I still have the same occasional parasitic draw.
I can fix this issue for you. I'm a dealer for AntiGravity batteries and it's awesome and lithium ion and sites at a resting voltage of 13.1 volts. Has bluetooth to monitor everything and weekly reports. I've sold these to my Ferrari and Lambo customers as those cars suck for draw, horrible. This will fix the issue. If you're thinking about this let me know and I'll help you out.
I am looking for some ideas how to find this parasitic drain
What I know that many times in a 24h period *something* in the car gets activated and then draws 3.3 - 3.4 Amp for 20-40 seconds.
Naturally this is very hard to troubleshoot
I tried some reverse engineering: I tested the current across each fuse using an "AmpHound" to see if there is anything that draws this kind of current.
And it turns out that the fuel pump draws exactly this current.
So I pulled the fuse for the fuel pump and did a long time test again, unfortunately I still have the same occasional parasitic draw.
And by now I'm pretty much out of ideas...
Find an indy with Xentry or go to dealer... the latter will so have have additional tools to data log can bus activity if needed. Otherwise continue to pull fuses, one each night... If you really want to go crazy, instead of measuring total draw at the battery. Measure it across each circuit (fuse) and log it over a 24 hrs period. That'll help narrow it down... at the expense of TIME.
Interesting. I was just looking at something the other day about using Xentry to disable Tele-Aid completely. I thought at the time it wasn't a bad idea, it's of utterly no use to me (or anyone else, I'm sure). I wonder if doing that would prevent the module from powering itself on, or not.
and i should probably add that me measuring the battery draw over 24h (see first post) was apparently a red herring.
I still have the same pattern but now the car still starts after 5 days (before the tele-aid module was pulled) the battery was dead on day #3
I also bought and installed an Antigravity Batteries AG-BTR-1 Battery Tracker, which allows me to check the battery voltage from remote, very convenient. (My car is parked on the street, it doesn't fit in the garage)
Interesting. I was just looking at something the other day about using Xentry to disable Tele-Aid completely. I thought at the time it wasn't a bad idea, it's of utterly no use to me (or anyone else, I'm sure). I wonder if doing that would prevent the module from powering itself on, or not.
You could use Xentry to update the Tel-Aid module to mBrace.
True it won't remote start the car but the car locator and remote door locking and unlocking work.
Color me very unimpressed. In over four decades of driving I have never yet lost a vehicle. Remote lock and unlock? If I forget to lock the car, I'm not going to remember until I get back to it. And you can't really lock your keys in one of these. Mine won't lock the doors if there's a key inside, and won't latch the trunk if there's a key in there, either. We figured that out the first time we tried to leave my wife's purse in teh car when we were at some event or other -- she had to take her key out of her purse before we could close the trunk.
Like Night Vision, it's a gimmick with very little or no practical value. I wouldn't need or use it if it were free, and it's far from it. I pay quite a bit less for AAA than Mbrace would cost, and it's actually occasionally useful. So I think I'll pass, thanks.
and i should probably add that me measuring the battery draw over 24h (see first post) was apparently a red herring.
I still have the same pattern but now the car still starts after 5 days (before the tele-aid module was pulled) the battery was dead on day #3
I also bought and installed an Antigravity Batteries AG-BTR-1 Battery Tracker, which allows me to check the battery voltage from remote, very convenient. (My car is parked on the street, it doesn't fit in the garage)
OP, were you able to isolate and resolve this drain? I’m looking to purchase a 09 s550’ from a friend but the car also has a parasitic drain.
the rain light sensor stays awake as it can close the windows and sunroof on its own... it would also see changes as the light level alters... its a mad module the OCP programming turns the car inside out and upsets everything
after the original pre facelift cars were made - Merc started on a journey of special extras magically built in software.... likely to ensure you struggle or stay within the dealer network burning money for fun
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
