ralph69

Hi,

I recently replace my old ML350 for a 2015 ML350 and after a few weeks a 2-3 time weeks truck won't start because the battery was dead over night.
I finally kind of located the problem and need your feedback before going back to the dealer.

Whenever the push to start button is inserted, eventually the battery end up dead over night.
I realize that If I don't insert it, don't use it at all, I have no battery drain.
Then I push my test further and use it to start the car but always remove it when I get home or park the truck for a long period of time and so far I still have no battery drain after 1 week.

What do you think could cause the battery drain when the button is in the socket?
I went to the dealer before my tests, they kept it for 2 weeks and they never had any issues with it, this time I want to keep the $$ to a minimum by having as much info as I can.

Thank You

we47b1me

how far away is where your keys are at night compared to where the truck is? Also, you should scan the keylessgo module with a pro level scanner

ralph69

I know where you going with this, was also my first reaction but i'm far enough I would say easily 20-25 meters and when I went to the dealer I notice the keys was actually closer to truck.
And I had a 2011 also with keyless, truck and keys same spot for years and never had any issues.

I actually ask the dealer a few days ago if he was starting the car with the keys or button and told me both. so my guess is that the button was not always in the socket and since it random when the button is in the socket, he never had the problem during the 2 weeks.
I even for fun borrow a friend button and after the third day the battery was drain over night.

peter2772000

Have you checked the amperage draw with the truck off?

I've got an issue with my mom's 07' Taurus, we must've replaced the battery at least 4-5 times. Goes dead if it hasn't run in over 2-3 weeks. It's in my garage now and tests show a draw of .3 amps with everything off, which is way more than acceptable. You'll have to start pulling fuses one-by-one 'till you find the guilty circuit.

vrmb

I know this is old thread, but wondering if you ever resolved this issues. I'm facing exactly the same situation on my 2012. Button kills battery after day or 2. I noticed couple of symptoms, that if I have button inserted, and sit in the car for around 5 min, feels like some relay or something else keeps clicking every min or so, and it seems somewhere under passenger side seat, where battery is located. If no button present in ignition, no sound. I also did battery draw test, with button in it draws about 5 Amps, without 0.2-3.

we47b1me

if your fob is within 10-20 feet of the car, then that is your problem. It's constantly pinging back and forth the keyless go module.

If your fob is far away from your car, and you are still hearing that relay like sound click (the keyless go module is under the carpet, and an antenna in the center console), then something is triggering the system and you need to have it scanned.

vrmb

I will probably will have it scanned. I have it for 3 years, keys are more or less are kept at the same place all the time probably, within 20 feet. This is also second battery with past 9 month, last one 2 weeks ago. If I drive car daily, no issues, but if it's not touched for a weekend it's dead. Does anyone know know if 5 amps draw is normal for this truck if button is in ?

Thanks!

we47b1me

Put the keys 30+ feet away, see if it dies over the weekend.

peter2772000

.3 is still way too much. You should have a draw of no more than .03 to .05 after the car's been off more 10 minutes or so. I've gone thru this exact issue with my Mom's Taurus which chews the batteries with a ferocity never before known to mankind. It pulls .4 amps and the battery is stone dead within 3 weeks of non-use.

vrmb

I will see how it goes with button off first... then with if battery still alive by Monday. Just curios why it would start drawing that much with button in....

vrmb

3 weeks it's long time for me not to run it, if it lasts 3-4 days I would never notice. I will see if I can do test again, maybe it was .03 and not .3

vrmb

Just to update, after removing push to start button battery did not discharge in few days..... now I need to figure out why push button drains battery..... anyone has any ideas ?

we47b1me

did I not suggest moving keys further away than where you have kept them? Did you do that?

vrmb

Not yet, got 2+ feet of snow, don't want to dead with deal battery if something happen . Will do that test later.

we47b1me

why don't you do that first? Don't understand advice given, ignored, and then asking for more advice...smh

vrmb

And what fix that would be if that is the case ? Park car or leave keys at neighbor house ?

we47b1me

Huh?

peter2772000

LOL, he's got a point.

PeteyV

Sorry to revive an old thread - but what was the outcome of your battery? Did you end up placing your keys further away from the vehicle?

vrmb

I pulled push to start button out and using key instead to start ...had no issues since then.