[jkkjroberts]

We have a 2011 MDX and about a year or so ago, we started having frequent battery drain issues. Acura dealers check out the battery and the electrical system and everything is fine. They tell us that we should not be using the 'accessory function' in the 'turn the key forward' mode.

The battery literally drains to only a click in a matter of 30 minutes of use in this manner. I did this as recently as yesterday, had to get a jump start and it probably took 5 minutes of connection to get started again.

Acura tells us this is normal and to not use the accessory function, ever.

Two oddities, 1) I have never had this issue with any other car and 2) I did not have this issue with this car for the first 4 years of ownership.

Can anyone confirm that this is 'normal' and if not, do you have any suggestion as to what might be the issue?

Thank you! My first post.

Michael J Roberts

 

[Priscillababy]

We have a 2011 MDX and about a year or so ago, we started having frequent battery drain issues. Acura dealers check out the battery and the electrical system and everything is fine. They tell us that we should not be using the 'accessory function' in the 'turn the key forward' mode.

The battery literally drains to only a click in a matter of 30 minutes of use in this manner. I did this as recently as yesterday, had to get a jump start and it probably took 5 minutes of connection to get started again.

Acura tells us this is normal and to not use the accessory function, ever.

Two oddities, 1) I have never had this issue with any other car and 2) I did not have this issue with this car for the first 4 years of ownership.

Can anyone confirm that this is 'normal' and if not, do you have any suggestion as to what might be the issue?

Thank you! My first post.

Michael J Roberts

1.) Welcome aboard Mr. Michael!...

2.) While I may be stating the obvious, NEVER rely upon/believe everything that the Acura stealerships tell you...there are some Acura service advisors that do NOT even know the difference between an engine air filter and a cabin air filter (NOT joking!!- even I know that distinction and I'm a self proclaimed numb-nutts when it comes to garage shop talk!), and whose primary concern is solely to get you to agree to having as many service items performed (even if not needed!) on your MDX all in the effort of either satiating their service advisor weekly quota's, or to prevent them from having to look for a new job at Best Buy (i.e. Geek Squad etc.)...yup!...I know that sounds cruel, but I have been tea b***** by many Acura stealership advisors over the years due in part to their idiocy/greed in conjunction with my own naivety when it comes to understanding car talk

3.) The SEARCH BUTTON IS YOUR FRIEND: :29:
*now you best be prepared to do some reading!!! :nerd:

http://www.mdxers.org/forums/74-second-generation-mdx-2007-2013/55801-battery-keeps-dying-2008-mdx-brand-new-battery.html

http://www.mdxers.org/forums/74-second-generation-mdx-2007-2013/94610-08-mdx-parasitic-drain-c-clutch-relay.html

http://www.mdxers.org/forums/74-second-generation-mdx-2007-2013/143833-dead-battery-issues.html

http://www.mdxers.org/forums/74-second-generation-mdx-2007-2013/27238-2007-mdx-electrical-battery-problem.html

http://www.mdxers.org/forums/74-second-generation-mdx-2007-2013/128050-quickest-way-detect-hfl-battery-drain-issue.html

http://www.mdxers.org/forums/74-second-generation-mdx-2007-2013/39832-2007-acura-mdx-not-starting-not-battery-alternator.html

4.) If you don't feel like reading through any of the related threads above and just wanna cut to the chase- manually pull out your 2nd gen. MDX's bluetooth module (the likely culprit)- accessible from the rear of the center console section, to see if the power drain stops?

And lastly, and interestingly enough, if your particular battery drain issue is in fact related to the notorious 2nd gen. MDX bluetooth (HFL) related battery drain problem, there's actually a class action lawsuit that you can sign your name up for- you can read further about this by clicking on the link below...in principal, by signing up you would be amongst the beneficiaries of any reward/settlement obtained by the principal plaintiff liar(s) (I mean lawyers) should the judge happen to rule against Acura:
http://www.mdxers.org/forums/74-second-generation-mdx-2007-2013/145402-class-action-lawsuit-against-honda-bluetooth-module-hfl.html

 

[jkkjroberts]

Thank you! I will definitely check out the links and the reading!! I appreciate your quick reply!

 

[wasjr]

I have had three MDXs, including my current 11 Advance, and have never had this issue. I did have batteries replaced after about three years under warranty in my 05 and 11, but not from any particular issue.

 

[mrgold35]

I had the same issue with my 11 MDX Adv. Found out the hard way when I updated my navi map in the garage. I just turned on ACC since I figured it would only be a 10-15 min update. The MDX wouldn't start after that short amount of time (3yr old battery in 2014). I always had enough juice to start the MDX; but, too scared to run even the radio without the engine being on. I later added a Blackvue DR650 front/rear dashcam and the crappy OEM battery just couldn't keep up. I upgraded to an Interstate AGM and zero issues since.

I seem to only get 3-4 years max from OEM Acura batteries. I always get full life and power from the Interstate battery replacements.

 

[JRB]

I had the same issue with my 11 MDX Adv. Found out the hard way when I updated my navi map in the garage. I just turned on ACC since I figured it would only be a 10-15 min update. The MDX wouldn't start after that short amount of time (3yr old battery in 2014). I always had enough juice to start the MDX; but, too scared to run even the radio without the engine being on. I later added a Blackvue DR650 front/rear dashcam and the crappy OEM battery just couldn't keep up. I upgraded to an Interstate AGM and zero issues since.

I seem to only get 3-4 years max from OEM Acura batteries. I always get full life and power from the Interstate battery replacements.

I got almost 7 years out of mine, but it didn't die the way I would have liked. I arrived early for a hockey game, so I decided to play with my phone while charging it, without the engine running. Big mistake! Battery was dead as a door-nail, so I had to call my wife to have her drive down with my "Jump 'n Carry". With that hooked up, the MDX started right away. But since the OEM battery was nearly 7 years old I figured it was on its last legs anyway, so I had it replaced by a trusted mechanic. Before putting in the new one (Costco), he load tested it and confirmed that it was very much due for replacement. So all in all I can't complain, no fault of the car that I can see.

 

[mrgold35]

I've notice I still get a battery drain; but, it takes a few days of sitting before the MDX complains. I thought it was my Blackvue dashcam pulling too much power in parking mode. I have power management device that cuts power to the dashcam if power gets below 12.2v. I've taken it to Acura to check out and they said everything is fine. The larger capacity of the Interstate AGM battery just gives me a few days instead of a few hours with the old OEM battery. I have a battery maintainer and top off the battery every weekend.

 

[r10]

My issue is still persisting

I have been following this thread for some time now as I been experiencing the sudden battery drains as well. After several replacement batteries and tests, I disconnected the HFL several weeks ago and the MDX has been behaving nicely, so I was congratulating myself for solving the problem. Well, all of sudden, I have a dead battery again. I've had the battery checked and tested and it appears to be fine, so I am now left wondering what else could be the source of my draining? Any suggestions, links or recommendations would be very much appreciated.

 

[thegazelle]

I have been following this thread for some time now as I been experiencing the sudden battery drains as well. After several replacement batteries and tests, I disconnected the HFL several weeks ago and the MDX has been behaving nicely, so I was congratulating myself for solving the problem. Well, all of sudden, I have a dead battery again. I've had the battery checked and tested and it appears to be fine, so I am now left wondering what else could be the source of my draining? Any suggestions, links or recommendations would be very much appreciated.

If it is not HFL obviously, then check the A/C relay in the under the hood fusebox. If the A/C relay is made by Omron, change it...the replacement relay part is a Japanese named brand (begins with an M), made in Vietnam. I got it directly from the Acura dealership for around $40.00 Cdn. Will post the part number when I get home later tonight. I changed mine out last month.

 

[r10]

If it is not HFL obviously, then check the A/C relay in the under the hood fusebox. If the A/C relay is made by Omron, change it...the replacement relay part is a Japanese named brand (begins with an M), made in Vietnam. I got it directly from the Acura dealership for around $40.00 Cdn. Will post the part number when I get home later tonight. I changed mine out last month.

Thanks for the suggestion. So, when I get in the under hood fusebox, I am having a very difficult time reading the writing under the plastic lid and I really am not sure which part is the A/C relay. Is it possible to tell me which one to replace in this attached picture? Much appreciated!

 

[thegazelle]

Thanks for the suggestion. So, when I get in the under hood fusebox, I am having a very difficult time reading the writing under the plastic lid and I really am not sure which part is the A/C relay. Is it possible to tell me which one to replace in this attached picture? Much appreciated!

I have attached a photo showing where the AC relay is after I switched it - I circled it in RED - mine was an original Omron one with white writing but is now the newer Honda/Acura (Mitsuba) one with faint writing. Part number is 39794-SDA-A05. I purchased directly from Acura dealership.

It is weird in your photo - either you don't have one (it's a blank) or it's something else. The battery drain issue caused by the faulty relay is related to the Omron original one.

 

[r10]

I have attached a photo showing where the AC relay is after I switched it - mine was an original Omron one with white writing but is now the newer Acura (Mitsuba) one with faint writing. Part number is 39794-SDA-A05. I purchased directly from Acura dealership.

It is weird in your photo - either you don't have one (it's a blank) or it's something else.

Wow, that is strange. Anyone on here know why I would not have a AC relay? Guess that would not be the source of my battery drain since I don't have one plugged in.

I did go ahead and remove the current blank plug and have attached a picture. The only writing is what is show here on the side.

 

[thegazelle]

Looked up that part. That is not a blank. That is a Toyota AC relay. Not a Honda Acura one. Replace it with Honda/Acura OEM part number i gave you


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[r10]

Thanks. Part is ordered. I'll keep you posted how it all works out.

 

[bivey77]

Similar Issue in my 2010 MDX

Hey Guys, I'm having a problem in my 2010 MDX with tech package. It started a week ago on Sunday. Came out to the car not starting, had it jumped by a friend and we drove it for over an hour and parked it back home. Next morning, dead battery again. I tried jumping it, but with no luck. Honestly, I didn't try very hard since the car alarm went off every time I connected the jumper cables. I disconnected the battery and took to Sam's Club to have it checked. They said it had some bad cells and would only charge to about 8V. I bought a replacement (Duracell) and put it into the car. Wife drove it around town a few times for the next few days, without any issues. On Thursday, my wife calls me and tells me that the car won't start again. That's when I start doing a ton of research. I disconnected the HFL and had the car jumped. It ran fine the rest of the day. Next morning, battery's dead again. I checked the A/C clutch relay, and actually swapped it with the fog lamp relay just to be sure. Had it jumped and took it to NAPA to have them check the battery and alternator, both check out fine (in fact battery is providing over 800 CCAs). So I went and bought a multi-meter and connected it in series between the negative battery terminal and the neg post. After it has been sitting for a couple of minutes, the current draw drops to .02 Amps and remains there. I kept the multi-meter connected for most of the day and checked back every 30 mins or so and it was always between .02-.03 Amps. Yesterday (Sunday) my wife drives it and gets the "replace battery" warning. I checked the voltage and its at 12.7V. I kept checking everything all day yesterday and it seemed to be ok. About 9 pm last night, I checked again and it was about 12.65V after sitting all day. Then I checked on my way out to work this morning at around 6 am and it's down to 11.6V. What is going on? How can the battery be draining if it's only pulling .02 Amps? Is something turning on in the middle of the night? I'm going crazy trying to track this down. Any and all help is greatly appreciated. Thanks!

 

[thegazelle]

Is the fog lamp relay the same as the AC clutch relay? How do you know if that relay was actually good? If if were me I would replace it with the OEM Honda/Acura one 39794-SDA-A05

Do you have any type of cell phone chargers attached to the car or anythig else plugged into the lighter or the 110v port? The previous owner of my BMW had a dead battery after it was discovered she left phone charger plugged into it that was somehow draining the battery. I had to read the service record twice to believe this.


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[bivey77]

Yeah, that's a good point. I'm not entirely positive that the fog lamp relay is good, other than the fact that I didn't see the fog lamps stay on after the vehicle was shut down. I'll order the new relay(s) just to be sure.

Is it possible that the new battery is toast since it drained and was jumped 2-3 times in the last week?

Thanks thegazelle!

 

[bivey77]

And no, there aren't any chargers or anything plugged in. Both my wife and I have been over the entire vehicle multiple times looking for lights and chargers. Good thought, though

 

[r10]

Thanks. Part is ordered. I'll keep you posted how it all works out.

I replaced the AC relay with part you suggested. Good news is that I have had no further draining issues over the last ~45 days. I am optimistic that between the HFL being disconnected and replacing this relay, we've got it nailed down.

Unfortunately my AC is not blowing very cool. This was an issue before replacing the relay. Guess it's time to go get the system recharged. Has anyone here done one of those DIY AC kits that are now be sold in Home Depot and Auto Parts stores?

 

[Alpine003]

I replaced the AC relay with part you suggested. Good news is that I have had no further draining issues over the last ~45 days. I am optimistic that between the HFL being disconnected and replacing this relay, we've got it nailed down.

Unfortunately my AC is not blowing very cool. This was an issue before replacing the relay. Guess it's time to go get the system recharged. Has anyone here done one of those DIY AC kits that are now be sold in Home Depot and Auto Parts stores?

I've done the diy recharge kits a few times now on various cars. AC shouldn't be escaping at all and doing this is most likely a bandaid that you will have to repeat later. Sometimes if your AC clutch relay goes out for awhile, it can damage your compressor and thus possibly providing some kind of leak in the process.

Personally, I would either get a diy dye kit or take it in to have it professionally dye tested for any leaks. Or you can chance it and get the r134 recharge kit but make sure you get the one with the gauge so you don't overcharge it.