I'd like to create a comprehensive thread on all known RDX battery issues because there are a number of them I have encountered. Here is what I know to be possible causes:
1) HFL - the handsfree Bluetooth module drains the battery and is the most common cause. Unplug or replace HFL.
2) AC clutch - the relay can get stuck "on" and the clutch never disengages and drains the battery. Replace relay.
3) Stereo Amplifier - it's down there with the HFL under the center console and it needs to be replaced. It has it's own fuse so you can test it for battery draw, but on my car it was intermittent.
4) Door lock actuator - when you press the door lock/unlock, one door lock can get stuck locking (or unlocking) and drain the battery. I have not had this myself but I have heard that you'll know it by the door not unlocking or locking when it should and/or the alarm doesn't arm on the double press of the remote. Don't forget about the back hatch door.

On #3 above (Amplifier), I would really love to read the TSB on this. The number is 07-064 but I cannot find the actual TSB anywhere. I'd love to see what it says as I believe this is my problem.
So many parasitic draws in one car - ugh. Anything else you guys have seen?

 

 

 

How can I unplug my hfl? Is there a certain fuse I can pull that controls this?

 

TSB 07-064 - Battery Discharges for No Apparent Reason
Applies To: 2007 RDX w/Technology Package - From VIN 5J8TB185.7A000001 thru 5J8TB185.7A013757
http://www.urvi.net/forumfiles/SB/B07-064.PDF
http://techinfo.honda.com/Rjanisis/pubs/SB/B07-064.PDF

 

Well that ends that discussion!! Great info provided there EE

 

 

I replaced the battery and alternator but it still kept draining every 2 days of sitting outside. Took it to the dealer today and they disconnected the HFL unit and now everything is fine again.

Hope this help someone before you go through what I did and spend unnecessary money.

 

Did they have any fix for the HFL instead of just leaving you without it...?

 

Here are possible solutions to bad HFL:

Install a different module, aftermarket, either in the glove box or console.

Bake it in the oven, somebody else on this site has the details regarding temperature, duration why and how long it might work afterwards, maybe a different model though.

Buy another new or used.

 

bake 380-400f for 8-10min (make sure to remove the plastic case!) and DO NOT move it while hot or you might drop some chips. "Fixed" the HFL board twice but only lasted 6 months. took it out couple years ago as I was done with drained battery and flaky BT anyway... 07 MDX - what year is yours ?

 

Thanks for the details, was sure I had read about such "hot" solution.

08 RDX, base. Little use of the HFL, so I can take my time, bigger issues to address until then.

 

dealer wants $500+tax for part, found online for $320, but I may seek aftermarket as I don't want to give acura $$$ for bad parts when they should have recalled those..

 

Hi, I know this thread is old. Just wondering if anyone had replaced hfl module themselves, if so did you then have to take to dealer to have it programmed to your car?

 

No programming needed. Just swap it out with the original unit

 

Thanks! that's good at least, dealer wants $527 just for the part. By any chance do you know if the one for 07 RDX can be baked like the one for TL? If I can get it out, I was thinking about giving that a try first

 

If you’re going to replace it anyways I don’t see the harm in trying it out.

 

I noticed my car taking a little longer to start. Tested OEM battery and there was a dead cell. I drive 90 miles to work round trip but use remote start regularly and get in before it cuts off after the 10 minutes, allowing enough time to charge. I don’t do anything out of the ordinary (I would think) to cause this.

Luckily I was covered under warranty for it (46k miles of the 50k mile new car warranty). Reading this thread and a few others, apparently there’s ongoing issues with batteries in Acura- hopefully mine will last.

 

Acura stock batteries are trash and so is the charging system. I change my battery every thirty thousand miles. What a joke the parasitic draw is on these vehicles.

 

My RDX has mysteriously started dying every few days the past few weeks. HFL is fine and the battery (1 year old) and alternator test out ok.

 

I fixed mine with this It's a little annoying, but a cheap fix.

 

Get an optima yellow top only battery that won’t be killed by the rdx

 

Okay, so since may of this year I have replaced or removed:
alternator (twice)
battery
tensioner pulley
HFL disconnected.

May: replaced battery
may: replaced alternator & tensioner pulley
still having issues so I pulled the HFL. Tan fine for a few months.
first time replacing alternator and tensioner, car ran for a month or two before crapping out again.
October:
Replaced the alternator again a couple weeks ago after I was getting warnings that my battery was being overcharged and every light imaginable came on. Ran for about two weeks or so.
Dec:
now that I replaced the alternator again a few weeks ago, I went to start my car and the battery was dead.
At this point I just want it to run well enough to trade it in. What could be causing it?

 

Posted reply in the other thread if it helps

 

I replaced the HFL, but found another drain caused by the moonroof. Is the moonroof a known issue? I removed the fuse and disabled the moonroof to stop the drain.

 

Ironically I received a letter in the mail yesterday about a Small Claims against Acura that is a result of the Bluetooth problem and battery draining. My 2007 RDX experienced the battery drain too.

 

Just got this as well. I have a 2019 RDX that just returned from the shop because it died on me twice in the last month. Replaced battery. Dealer says it's because there's so much tech on these cars not running them often enough will cause this. It did happen after being gone for several days both times. Frankly I'm scared it's going to happen again when I'm out somewhere with kids in tow. Dealer says "they've seen this with Covid and folks not driving as much."

Is this a load of crap and should I push for a better solution? Is there truly a better solution? Better battery?

 

I think the dealers don’t know the correct answer. When the Sat Nav in my 2002 CL-S went bonkers, the dealers were stumped, until millions of calls into Acura. From my understanding, the Bluetooth module is whacky and drains the battery, as well as possibly having Dolby chosen in the Audio menu. I’d you have it ON, the Dolby amp is always on and drains the battery. Minor issues like a bad starter, can cause battery drain, but my mechanic said that isn’t viable.

 

Hello everyone,
I think I have an amplifier issue in my RDX 2011. I pulled fuse # 31 and the current dropped from 1.2A to around 40mA. I noticed the current is kinda jumping or pulsing if you will. Not sure if it's normal or should I check anything else. The bluetooth module has been disconnected already.
The question to who already has some experience replacing the amp - how difficult / easy was it? Did you do it yourself or at the dealers? Is the radio amp still available somewhere? If not - is there a third party amp that fits Acura RDX 2011?
I appreciate any advices!
Thanks !

 

I ordered a used one online and swapped it myself. In my 07 it was underneath the center console. You pop off both sides and scoot the seats all the way back. Pretty easy.

 

Thank you!

 

Well I'm a new to me 1G RDX owner and this was very helpful. I got the car at 209k (km) and replaced the starter (weak starts after new battery) and the radiator with a denso, gates rad hoses, did a 3x3 trans flush, replaced the oil, rear diff, transfer case and power steering fluids, serpentine belt, spark plugs and engine/cabin air filters all from info from this site. Then, out of the blue, the battery was dead...
so I read some more. Then I disconnected the BT handsfree unit, replaced the A/C relay with the mitsuba and added this disconnect when I'm away from home for a few days and everything is good (for now lol)
many, many thanks for all the info fellas I am very grateful for all of you and this site.

good luck,
FCF

 

AnybodyAnybodthe driver door actuator draining your battery? I jad to disconect mine because it will drain it within hours. Thanks