Hello!
I've read other threads about the HLF draining battery life and how to remove it but my question is, does it need to be replaced or can I just remove it? I saw a comment about a cheaper aftermarket replacement that goes into the trunk and actually allows for Bluetooth connectivity, which my 07 TL does not at the moment, so does anyone know if you would just remove the stock HFL module and install the aftermarket one? If so, anyone recommend any aftermarket ones? I am not going to pay $400 for the replacement HFL module LOL

 

Remove it


/endthread

 

So I can remove it completely with no problems after?

 

besides an annoying message on the dash saying "Check HFL system"

 

UGH, that will be annoying.... no way to disable it? Is there a 'dummy' unit that can be put in to stop the notification?

 

The megathread would have a workaround if there was one.

 

Sorry, new here.... megathread?

 

Wait... in what way it's annoying? If you browse options you will find it, but it doesn't pops out like low tire warning

Here's long for that thread:
https://acurazine.com/forums/3g-tl-p...nk-fix-900427/

or

https://acurazine.com/forums/3g-tl-a...-drain-948481/

 

You don't even have to remove it. Just unplug the connector to the HFL module. Just try it for a while. Better than having a dead battery.

I don't even notice any message. Nothing pops up for me.

 

The only way to know that HFL is removed on my car is to either press call button on the steering wheel, and nothing happens, or navigate to the HFL menu, and it will say that it's booting or unavailable or something.

There is no message that pops out every time you start the car or anything like that.

 

I bought my '07 TL exactly 2 years ago. Within a few months, had to replace the battery after leaving it parked at the airport for a few days (wouldn't start upon my return).

After poking around on this forum for a few days and reading about the parasitic battery drain, I disconnected the HFL unit above the dome light. Haven't had any real problems since, even after leaving the car to sit for an entire week last summer.

So, now my battery is about 20 months old. Last month (Jan. 2019), took the car to the shop for routine oil change and state inspection, and my mechanic tells me to keep an eye on the battery because it's "weak."

So, my questions are:

-Is replacing the battery every 2-3 years "normal" for 3rd gen TL's? (I was looking at a Carfax report for a 1-owner '07 TL-S that's for sale locally and saw that over 11-12 years [and 68k miles], the owner had to replace the battery 3 times--including the factory-installed battery, that's 4 batteries that've been in this 12 year old car.)

-Is simply unplugging my HFL unit above the dome light enough to prevent parasitic battery drain?

I'm not very mechanically adept, nor do I have the tools to do a proper trouble-shooting on my own. What specifically could I ask my mechanic to check in regards to a brand new battery becoming "weak" after only approximately 2 years?

Thanks in advance for any help, guidance, suggestions, etc.

 

I suppose the every other year question is relatively, uhhh, relative. I mean, a run-of-the-mill grade battery may well only last two years, higher end batteries may last longer. The battery in my 2006 (with a still functioning HFL) was in the car when I bought it in May of 2017; it feels a bit soft when I start the car on sub-zero mornings, otherwise no issue.

The above said, I broke my leg this last Tuesday and per the orthopedic sturgeon [sic], I might be able to start clutching late next week, so the car will have sat at least eleven days between starts; should be interesting.

 

Thx, horseshoez. Apologies for not being more specific re: the battery.

About 23 months ago (late March 2017) I installed an "Interstate Mega-Tron Plus [MTP] 24F" rated at 940 CA (cranking amps) and 750 CCA (cold-cranking amps).

My paperwork says it comes with a "30 month free replacement or 6-year performance warranty," although it hasn't actually "failed" as of yet (only deemed "weak" by my mechanic), and even if it does "fail" in the next 7-8 months (which I don't anticipate), it may be due to the TL's notorious issues with battery drain and thus not be under warranty.

Anyway, thx again. Sorry to hear about your leg, and hope you're back to full-strength soon!

 

Thanks man, appreciate it. If/when the battery fails, even though you'll be outside the 30-month window, they should still pro-rate a new battery based upon the 6-Year warranty.

When the battery in my TL goes Tango-Uniform I'll probably put a Honda 100-Month battery in it. I had one of those in my 2001 V6 Accord and it lasted nine-years and ten-months before failing. Yes, I know there is no way it will last that long in a TL, but that means the pro-rated warranty period will be eight years and four months.

 

Hello everyone, I hope this will help end some of you frustrations with the dead battery syndrome from the HFL. I had the same issue with my battery dying after sitting for two or three days. After 3 battery replacements I decided to search accurazine and quickly realized I am not alone with this problem. The HFL is the reason for the battery drain for most of the Acura cars. I disconnected the HFL and the problem was solved. But I could no longer use by Bluetooth and hands free commands which is not ideal. So I decided to dig a little deeper into the problem as I have a lot of knowledge on circuits and I use to work in car audio back in the late 90's. The first thing I looked for was a wiring diagram of the HFL gray plug. I found on the wiring diagram and there are two pins that give power to the HFL. Pin number 15 Gry/Blu which is a constant 12 volts and pin number 16 is Yel/Red which gives it 12 volts when you turn the key to accessory. I quickly realized my unit was warm to the touch even after the car has been parked in the garage overnight. My HFL worked fine but I had several mornings where my battery was completely dead and I had to jumpstart it.

I am using a 12 volt bosch relay which is acting like a switch to turn power on and off to HFL with the ignition. I believe the issue is the HFL circuit board is suppose to stay on 30 minutes after removing the key from the car, however the unit gets stuck on for some reason and drains the battery. So I though why not put a relay in that will open the circuit on the 12 volt constant wire so when the car is off the HFL is off. All I am doing is using the relay to switch on and off the gry/blu wire which is usually12 volts constant going to the HFL. You will no longer be able to keep using bluetooth once you remove your keys as it will turn off power immediately to the HFL. So either keep the car running or turn key to accessory when parked and finish your conversation before removing key. That is the only difference, but worth not having to worry about a dead battery in the morning or after a long day at the office. Ask me how I know?? Here is what I did to fix the problem and it worked. I hate cutting factory wiring but this fix is only cutting one wire and tapping into another. So you really are not hurting the wiring much at all.

1: Peel back the tape on the grey harness that plugs into the HFL. You will cut he Gry/Blu wire and leave about 3 to 4 inches of wire on the harness plug side. (disconnect battery as this wire is 12 volt constant and you do not want to touch any
metal in the car with this wire)
2. You will need 20gauge primary wire and cut 4 12" pieces of wire to wire up a bosch relay.
3. Extend the wire you just cut by crimping or soldering one 12" wire to each side of the wire you cut to extend both sides of the gry/blu cut wires 12".
4. You will need a 12 volt bosch relay and connect the gry/blu wire on the car side you just extended to pin87 on the relay. The gry/blu wire on the harness side you extended will plug in to pin 30 on the relay.
5. You will need to splice or t tap another 12" wire into the yel/red wire (you do not cut the factory yel/red you just tap onto this wire) and plug this wire into pin 86 on the relay. This energizes the relay so the gry/blu wire can connect or disconnect with the igntion..
6. the last connection on the relay is pin 85 which you will run a 12" wire from pin 85 to any ground in the car( I used one of the bolts that hold the HFL panel in for my ground and it works great)
7. I would test and make sure you have 12 volts on pin 30 when you switch the ignition on and it should read no voltage when you switch the ignition off.
8 I then used electrical tape and taped up the wires and located the relay to the drivers side of the map, You will see a metal strip you can move to push the relay by the visor. Make sure all wiring is covered with electrical tape and away from any sharp metal edges.
9 plug in the HFL harness and put the car back together. You will no longer have any dead batteries and the HFL will work as long as the ignition is on.

This should work on 07 08 acura TL, you will have to get a diagram for the 04-06 as the harness is green so it might be different pins on the harness for the 12 volt constant and 12 volt accessory. Keep in mind my HFL works, it was causing a battery drain. if your HFL doesn't work at all this will not fix that problem. This is only for the battery drain.

Another thought I had was just cut the gry/blu wire and the wire that is on the harness side tap into the red/yellow and cap the car side of the gry blu so it will not touch any metal and short out. My concern is now you are relying on only one circuit powering the unit. Putting a relay in is using both circuits like the engineer originally designed, we are just switching off and on the constant now with the ignition.

Make sure you really understand what you are doing with the relay. Wiring the relay wrong could cause a dead short and possibly damage circuits in you car. Do this modification at your own risk. I verified all my connections with a meter to make sure it was reading the voltage correctly. I am using the same battery that was needing to be jumped in the morning and I no longer have an issue. Car sat for a week and started right up.

 

Everything that everyone is doing to "fix" the stock HFL is either a workaround or temporary.

Mine HFL went bad as well - battery drain but also Bluetooth stopped working. Found one IC that stayed warm all the time and re-soldered it with hot air. HFL worked again then to have it fail couple months later. I never tried again.

One more thing - using relay for something that will, at best, draw 0.5-1A is a bit of overkill. Like you wrote, cutting the "always power" wire and tapping it to "accessory power only" would work just fine. Depending on the relay, it might be even using more power than HFL itself.

 

If I read @Rick Feltman's write up correctly, there is no way the relay will draw any power at all while the key is out. Personally I think this solution is quite ingenious, true, once the rest of the HFL board goes Tango Uniform, it will need to be replaced, but my bet is the relay will significantly prolong its life.

 

I was trying to make a point about relay being overkill and kinda missed the point. Just having the radio on draws 5-6A so additional ~0.3A for relay and ~0.3 for HFL probably doesn't matter - of course speaking about having just acc on and engine off. With engine on you can do pretty much whatever with small loads like those.

Overall, as long as it works then it's fine. Just don't expect it to be permanent fix.

 

The relay is only energized while the ignition is on. Once you turn off the car, the relay is not pulling any current (In the resting position) and the constant lead to the of the HFL is an open circuit preventing your battery from discharging and needing a jump start. I am wondering if I put in a new HFL, if this would make it last substantially longer since it is never on when the key is removed. I know a relay is overkill but not sure how else to trigger it with ignition not tying them to the same circuit. I rather overkill and know it will work I guess. LOL.. Relays are cheap too..
One thing to consider, if your battery dies while talking when the key is in the accessory setting for 15 minutes or less, your battery needs to be replaced. The worst thing for a car battery is running them very low which is what the HFL was doing. This fix will prevent that but your current battery might have sustained damage due to it running low several times before the fix. Luckily my battery wasn't damaged and the car starts no problem. I think its sad Acura doesn't recall this and fix everyone HFL. I really do not see any side affects with this approach, however, my HFL still could malfunction like everyone else but it will not drain batter anymore. Think about traveling and leaving your car at the airport for a week, every time my batter would be dead when I returned and tried to start it. So frustrating.. Hope this helps.

 

I would bet HFL are going "tango uniform" due to heat cycling and cracking of the solder joints (damn you lead free solder!). That's why some people had luck with putting them in the oven, and why re-soldering that one IC on my board fixed it for a while. That is pretty common problem with BGA components and reballing is a common fix.

While still working and at rest, HFL draw very little current so it is pretty much stone cold. If that is the case disconnecting HFL will make no difference as it will heat up when running and cool down when disconnected anyways.

The "damage" to the batteries you are talking about is called sulfation and can be "fixed" to some degree if battery wasn't dead for a long time. Additional danger is that in discharged battery, electrolyte becomes pretty much just water, which can freeze, expand, and then damage the lead plates.

Like I wrote, relay is fine but "tying them to the same circuit" would work just fine due to low power draw of HFL. BTW I thrown out my HFL and used that circuit to power the dash cam and radar detector. That setup draws more power than HFL ever would from that circuit (probably ~1-1.5A at 12V).
https://acurazine.com/forums/third-g...e-idea-969096/

 

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First, I'd like to thank Rick for his detailed notes on this implementation. It really helped expedite my own on a 2011 RDX. My HFL/bluetooth unit was seemingly working well before this, but since this seems to be an inevitable issue and I wanted peace of mind, I decided to go ahead an preemptively solve this - and you can't go wrong with a $5 solution VS. another battery replacement.

I was able to follow these instructions and translated them to my 2011 RDX, so I thought I'd contribute my process for others here as well.

Accessing the unit in an RDX (with link):
In this case the bluetooth unit/ HFL is on the passenger side of the center console. I found a quick video on youtube that showed the way fairly well ( ). You have to roll the seat all the way back and pull out the floormat. Then you can reach your finger under but near the bottom of the glove box, where the side-carpet meets the plastic - if you try a couple of places you'll find one where you can pull the carpet straight away from where it's mounted. There are a few press clips that are pretty easy to pull out with a small amount of force (none of mine broke and didn't seem like they were even close to breaking at all). Then you want to get the fitment undone where the passenger's left toe would be near when they're seated, first. Then I pull that end, bending the panel a bit into a curve, then slide the panel toward where the passenger's feet go and it should come free cleanly. You'll see the module mounted sideways just below the cupholders. I couldn't get the plug free with my bare hands, it's too small of a space to get any lever on it. So, I unmounted the module by undoing the 2 10mil bolts in the upper right and lower left corner of the module. I still couldn't get the plug out, so then used a blunt-ish flathead to waddle it out while holding the tab.

The plug & wiring in this case - Bluetooth Module/HFL 28pin Plug on the RDX 2011:
Measuring with the multimeter indicated that the lower row, all the way on the bottom-right (if viewing the male/mating end of the plug with the securing clip on top), was the constant 12v. It's neighbor, immediately to the left of the bottom-right was the intermittent or only live 12v when the key is in accessory mode, otherwise this is 0v.

These wires were colored Green/Grey for the constant 12v, and the accessory 0v/12v wire is Purple/Grey. I double checked all the other pins and all had negligible volts coming across or none at all in any ignition position.

Wire specifics:
Green/grey [male/inserting end of plug (plug clip on top):
bottom right. From the back where all the wires enter the plug (with plug clip on top): it's the bottom left] --> this always has 11v-12v going to it no matter if the key is in or out or any other position in the ignition.The purple/grey is just to the left of the green/grey wire (if looking at the plug on the male side):
It's just to the right of the green/grey wire (if looking at the plug where the wires enter the plug or the 'back') --> has zero volts when car is off and keys are taken out of ignition, but has 11v-12v if the key is turned to accessory.

My quick look at what we're trying to accomplish in total:
The goal is to use the relay to break the constant 12v line. We cut this line and leverage the switching circuit in the relay (that's normally open/non-bridged) to re-connect this line by using the other, accessory powered line that's only delivering 12v when the ignition is in accessory or on mode. This second wire we tap into and this will flip the switch in the relay between pins 86/85 on the relay, we ground the other side of the switch flipper mechanism in the relay. So instead of always feeding 12v and relying on the Bluetooth module to properly cut power itself, we control this with the trigger wire.

Note 1:
There are different types of relays. I ended up with a SPDT relay (single pole, double throw) which is what you need or you could use a SPST (single throw) but it MUST at least have a normally-open (NO) circuit to it. SPDT will typically have both NO & NC (normally closed) or both 2x NO. I used chatgpt/gemini to help figure this out. You want the relay 'switch' to normally be disconnected/open, then when energized, only then we get the connection. My relay is an odd one, it happened to have 2 NO out-terminals. If you're in a pickle here and are unsure like I was (no documentation for the relay and both out terminals were labeled 87), I had went ahead and soldered my wires to the suspected 4 terminals, then hooked up a 9v battery and mocked the wiring like it would be in the car. I used a multimeter over the power switching terminal, you can also hear it click, but without a multimeter you couldn't see when power is delivered NO/NC (normally closed)... you could maybe get away with a spare LED with legs to see when & where the power is delivered. You could skip all the troubleshooting here if you just buy a 4-termnial SPST that's explicitly labeled as NO. Mine also had a bolt hole/tab that I was able to utilize to mount it, so that made it nice and tidy installing.

Note 2:
I would recommend building your wiring-harness-relay while indoors before starting as this takes a bit of time to ensure it's done right and the area is crammed as hell, my back had enough just trying to solder the pre-prepped wires of my relay harness. I couldn't imagine having to put it all together onsite. I only had 18g wire handy, but its rated higher than the 20g recommended wire (the wire in the car looks closer to 20g than 18g for sure though. I also sanded the terminals on the relay to get the solder a good hold, soldered the wire ends to it, then slipped a couple of shrink tube to insolate the bare solder joins. I also labeled the wires on mine, just so I didn't mess it up on install (built the relay harness one night, then installed the next... mostly due to having to troubleshoot my particular relay).
If you want to build this first, look at each terminal on the relay, there should be a number there. You will solder the 4 wires (in the steps below) to the terminals - just translate over which wire goes to which terminal number, and keep track or label them for easy reference later on. If you haven't soldered before, it's easy, just look up how and don't forget to pre-tin all your wire ends and the terminals on the relay.

Note 3:
when you're messing around under the center console, you might want a towel to catch any dropped bolts - just in case. I didn't and also didn't drop anything, but I probably should have. you'll see what I mean when you do this.

Steps are nearly identical, so I will include them here with edits/additions for the 2011 RDX:
1: Peel back the tape on the grey harness that plugs into the HFL. You will cut the GREEN/GREY wire and leave about 3 to 4 inches of wire on the harness plug side. (disconnect battery as this wire is 12 volt constant and you do not want to touch any metal in the car with this wire)
2. You will need 20gauge primary wire and cut 4 12" pieces of wire to wire up a bosch relay. [Mine were a little shorter than 12", but the recommended 12" or so is definitely needed, especially if you want to mount the relay so wires don't rub during miles of driving. I also had an off-brand relay.]
3. Extend the wire you just cut by soldering one 12" wire to each side of the wire you cut to extend both sides of the GREEN/GREY cut wires 12".
4. You will need a 12 volt bosch relay and connect the GREEN/GREY wire on the car side you just extended to pin87 on the relay. The GREEN/GREY wire on the harness side you extended will plug in to pin30 on the relay.
5. You will need to splice or t tap another 12" wire into the PURPLE/GREY wire (you do not cut the factory PURPLE/GREY wire you just tap onto this wire) and plug this wire into pin86 on the relay. This energizes the relay so the GREEN/GREY wire can connect or disconnect with the ignition..
6. the last connection on the relay is pin85 which you will run a 12" wire from pin85 to any ground in the car (I used one of the bolts that hold the HFL panel in for my ground and it works great)
7. I would test and make sure you have 12 volts on pin30 when you switch the ignition on and it should read no voltage when you switch the ignition off.
8 I then used electrical tape and taped up the wires and located the relay up to a 10mil bolt underneath the cupholders (you have to reposition yourself almost on your back to see up under there, there are 2 bolts, I used the one closest to me). Make sure all wiring is covered with electrical tape and away from any sharp metal edges. [I thread the wires in there so that there weren't any kinks or places where it would rub from driving - at least the best I could. I added some extra tape to any part that may possibly rub in the future]
9 Plug in the HFL harness and put the car back together. You will no longer have any dead batteries and the HFL will work as long as the ignition is on.

Images for the 2011 RDX HFL/Bluetooth module relay integration:

The relay harness - built before trying to install it. Added a washer that would make quick install under one of the 10mil bolts.
[img alt="The HFL/Bluetooth plug. We're viewing it from the front of the male/inserting end of the plug.
The securing clip for the plug is on top here. The 2 pins we need are the lowest-rightmost and it's neighbor, just to the left of the first. The lower-right is the constant 12v (Green/Grey), and the other is the only-12v-when-key-is-accessory-or-engine-on otherwise this has 0v (zero volts)."]https://cimg0.ibsrv.net/gimg/acurazine.com-vbulletin/1500x2000/img_20251103_180935879_690759339350c9d03319d187389 1c01d20825142.jpg[/img]
The HFL/Bluetooth plug. We're viewing it from the front of the male/inserting end of the plug. The securing clip for the plug is on top here. The 2 pins we need are the lowest-rightmost and it's neighbor, just to the left of the first. The lower-right is the constant 12v (Green/Grey), and the other is the only-12v-when-key-is-accessory-or-engine-on otherwise this has 0v (zero volts).

Another view of these 2 wires, but I tip the plug forward so we can see the back. The tolerances here are minimal - both with the available wire and space for hands. it's tough to work with bc you have to cram yourself in the small space to even reach it.

Freed the 2 wires after removing previous electrical tape (factory) and untwisting the bundle a bit.

Cut Green/Grey wire (constant 12v) and attached at the wires that go to the specified relay pin/terminal numbers. Spliced into the Purple/Grey wire by using a razor to scrape back until I saw bare metal wire - soldering then melts away some of the wire coating, but you want to have a good hold in the end, so be careful and sure you have enough wire to attach to.

After I reapplied electrical tape and bundled it back together, threaded the leftover ground wire up and back so it doesn't have tension and wont rub on any abrasive surface (added electrical tape to wire where possible 'touch' points could happen). The relay is up under where we cant see here; I bundled it in a way so it would fit here nicely. The ground wire with the soldered washer is sandwiched between the HFL housing and the metal bracket it mounts to (marked on photo).

Here we're looking up under to see how the relay is mounted (see previous photo for front-view). The marked bolt is the 10mil bolt under the cup holders just above this.