My battery has been dying at a very fast rate. Woke up to 4 dead batteries in the last 4 weeks. Took it over to Honda (closer to me than Acura) to have them diag it. Found the HFL was drawing about 350mA when car was off. Honda wanted $450 to replace it (no thanks).

Called Acura, they wanted $320 to replace. Cheaper rate, so let's get it done. Made an appointment to get it squared away.

Looked on this forum, found others had the same issue and are going way of DIY to fix. So I got home, pulled the center console apart, found the HFL and removed it. Battery draw went to 24mA. Stayed there for about 15 minutes. Perfect!

Called Acura to cancel my appointment and to buy the part directly, and was told I needed to drive down to pre-pay for the part, then they'd ship it to me. I don't want to drive 40 mins (one way) to pay for a part that I can't get same day. Gas is money. Especially to get a part for something I don't even use.

So my questions:

1) Any harm in leaving this thing unplugged? I don't use the HFL. Unless I can use it as a bluetooth speaker. Can you do that in the 2007 (like to playback Pandora, mp3s, etc)? Anyways, I saw 2 things that were odd (but since resolved themselves) 1 was the nav screen turned on, but AcuraLink did not. The other item was the car lock acknowledgment beep wasn't beeping. Both have cleared though and haven't found any other issues thus far with HFL unplugged.

2) Anyone know of an Acura dealer that'll sell me the HFL for a 2007 over the phone and ship to me?

Thanks!

 

Just checking in to see if unplugging the HFL completely solved your problem drsprite without any unwanted “side effects”. I have been battling the same issue with my 2007 MDX and have just unplugged mine to test.

 

So far so good. The only side effects are there is no Bluetooth link (as to be expected), and it seems the Nav voice recognition doesn't work. The voice prompt keeps saying 'Pardon' after I say something. This is another feature of the car I don't use very often, so I'm not too worried about it not understanding me.

Aside from those 2 things, everything else seems to be normal.

 

you can purchase through vendors here:
acktl05(aka bruce) who goes through curry acura in NY or tim at acura of peoria in AZ.

typically their prices are cheaper than dealer MSRP.

 

I thought about purchasing a replacement, but $200+ for a module I *never* use is a waste IMO.

 

Have you checked out the local salvage yards in your area for a totaled MDX? You might be able to find the part extremely cheap if you wanted to repair yourself down the road.

 

i use my HFL for my phone. actually i think i need mine replaced, since the blue tooth keeps dropping my incoming calls (it drops the phone from the car, but the call stays on the phone).

i was just answering the 2nd question. when and if you ever sell the car, i'm sure the future owner would like a working HFL unit.

 

My mothers MDX is having this same issue I think.. 2007 as well.
The battery is constantly being drained.
can someone provide steps with pictures on how to access the HFL wires and unplug them?
I'm not too familiar with wiring or the MDX itself.

 

Try this:

https://acurazine.com/forums/1-2g-mdx-2001-2013-166/hfl-module-mdx-2007-where-837013/

 

I also had the HFL fail in a 2004 TL. The module had actually been replaced in warranty by Acura in 2006 as the original had essentially unusable voice recognition. The replacement was only marginally better.
Recently though the HFL totally stopped responding, and the MID showed "booting." I do use the HFL, but I left it as for the time being. Then I went on a trip and left my car at the airport for about a week. When I came back the battery was TOTALLY dead. It was so dead that it wouldn't even take any charge with someone that was kind enough to give me a jump. In fact, it was so dead that I couldn't even open the trunk to get my jumper cables, so fortunately he had some. Given that the battery was about 3 years old I just figured the battery failed. I got a ride home and went back the next day with a new battery. The car started fine and I figured I was done. Then I left the car for a few days, this time in my garage and once again a dead battery with the brand new battery. Suspecting the HFL I pulled it out (with a charger now on the battery). I didn't actually measure the current, but it was quite noticeably warm when reconnected after only a few minutes. It was both the processor board and the power/analog board of the module, so it appears that something is messed up in the processor. It was warm enough to be consuming at least 1 to 2 Watts of power, easily enough to discharge a battery over a few days. I just removed the module from the car, and will see about finding a replacement. I'm positive the car will start fine as long as the new battery wasn't damaged by the deep discharge.
As for the Navi voice - in looking at the diagrams in the Service Manual it seems that the microphone in the top console is connected to the HFL module, and from the module it goes to the Navi. There appears to be a microphone pre-amp circuit on the bottom analog/power board of the HFL module. If I don't replace the HFL module I will at least restore the microphone audio connection to the Navi. I suspect that will require at least some type of microphone pre-amp. It appears, and it makes sense that Acura put the microphone pre-amp physically near the microphone in the HFL module, and then routed the higher level, lower impedance audio to the Navi.
As awful as the original HFL was, does anyone know of any 3rd party replacements that would work better and communicate with the communications bus to show call status on the MID?

 

Mine was replaced under good will warranty....saved me a bunch....

 

Part number is 39770-STX-A01 and can found online for $157 here:

http://www.acuraautomotiveparts.org/...p/mws/home.jsp

Replacing it is very easy. Remove the rear climate control panel:

Super easy to fix yourself. Sit in your backseat and pull as hard as you can on the air cond controls. Pull it straight back and hard enough to make you think it could break - it won't. You'll see the top pops off easily and the bottom needs a little coaxing, just keep pulling it straight back and massage it when it needs it. Once you get that off, there is a little black box right there with a bluetoothsymbol on it. The cable is really easy to remove, if you have to use force, you're doing it wrong. There is a little pressure button on the cable that will release it from the unit. That unit is what needs replacing; this is a common problem among MDX's, apparently.

 

the HFL in my 07 just died last week. looks like i know what i need to do.

any chance of getting one of these from the junk yard? did every Gen-2 MDX have HFL, or just some?


does anyone know what is failing? is it just one chip on the board? my brother-in-law is an electrical engineer and repairs non-working electronics all the time with a cheap resistor or something all the time..

 

I have had same issues with my 07 MDX, unplugged the HFL for 2 weeks all was good. Except that the clock and the radio were now disabled with it. I plugged it back in and dead battery again. Anyone know how to separate the HFL from the other two? I don't need the HFL- but want the others to work!

 

Clock and Stereo have nothing to do with the HFL unit... Check your fuses because the HFL does not mess with the clock or stereo.

 

Question. I just unhooked the fuse connector or cable plug thing from the HFL unit. Do I need to get a screw driver and physically remove the unit from the car or can it stay in place and be un "tethered" to stop the battery drain?

 

I leave it in place just unplugged... Mine is also a 2007 btw.

 

Great. I did see that the radio and clock are still active this time. must have been that I didn't hit the code to reset it last time. Car started this morning. One more question, I have my radio off when I start the engine, and the speakers always make this "pop" or click when I start up- does that happen to anyone else?

 

There is a TSB for condensation in the radio Amp causing those pops.. Supposedly the fix is to change the stereo Amp for a new unit that fixes those issues, Mine did those pops before but stopped (dunno why).. If I had to guess it stopped by the time I started to garage the car, It only did the pops when I leave it outside under weather.