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Discussion Starter #1
I have a 2007 MDX that has been experiencing a battery drain over the past few months. The dealer has checked both the battery (a 6 month old Costco) and the alternator; both checked out fine. The car is fine unless it sits for two or three days, at which time it is dead as a hammer.

Last night, after charging the battery with an external charger, I hooked up a digital multimeter between the ground cable and the negative terminal of the battery. There is a constant draw of 280 mA, with a 3 to 4 second spike of about 3000 mA every minute. This spike occurs very regularly. The 300 mA constant draw seems very high to me, I would expect something about 30mA. And the 3A draw is off the charts. I have no doubt that this parasitic draw is the cause of my dead battery.

Any ideas? I have researched this and other forums and have come across postings about the HFL, door locks, tailgate lock, and the AC relays. The TSB about the HFL does not appear to apply to '07, and I am not having any issues with the locks. Is there an easy way to confirm or eliminate the AC relay as the culprit?
 

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Those current readings don't look like the A/C compressor relay. That would be 1.5-2amps. What you're getting sounds like the HFL module.

Unplug it. Pull away the back of the center console (it just snaps on), and the HFL unit is underneath.
 

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put back your meter and try to unplug fuse one by one... you'l see what is draining .
I got the source figured out: it is the radio circuit. I pulled the 10A fuse for the radio, and the current draw dropped to about 15 mA. Before I pulled the fuse, I could hear some mechanical noises from inside the radio every time the current draw jumped up to 3A. The noise was kind of like the changer was trying to change disks. Does the radio circuit also control the HFL? I couldn't find a fuse marked "HFL" or anything similar.

Has anyone had a similar problem with their radio?
 

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Ruh roh shaggy. I've seen that one before. Audio unit will need to be replaced. And woo boy are they not cheap!
 

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Ruh roh shaggy. I've seen that one before. Audio unit will need to be replaced. And woo boy are they not cheap!
Could it be the HFL interfering with the radio? Do you know if the HFL is also on the same fuse as the radio? I am hoping it is "only" the HFL and not the audio unit. $1600 for the parts, online.
 

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On a couple of occaisions I ejected a disk while shutting off the car. The player tried to take the disk back as I was removing it. The only way to get it to stop was to feed it a disk and eject it again. Although I'll bet that Super Tech is right, I would still try feeding the system a disk (no ketchup) and see if that does anything.
 

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Try car-part.com to locate a used part. I would do a lot fiddling before replacing. It may be possible to remove and send for repair. The dvd player repair was not too bad ($180).

good luck
 

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Well, it turns out that it was the HFL causing the problem. The dealer diagnosed it on Saturday. They disconnected it, and now the current draw is down to about 20 mA when the car is sleeping. I guess this is good news, since the HFL is $700 compared to about $1600 for the radio. My dealership is contacting Acura to see if they will participate in the repair, since my MDX is just barely out of warranty.
 

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I have a 2007 MDX that has been experiencing a battery drain over the past few months. The dealer has checked both the battery (a 6 month old Costco) and the alternator; both checked out fine. The car is fine unless it sits for two or three days, at which time it is dead as a hammer.

Last night, after charging the battery with an external charger, I hooked up a digital multimeter between the ground cable and the negative terminal of the battery. There is a constant draw of 280 mA, with a 3 to 4 second spike of about 3000 mA every minute. This spike occurs very regularly. The 300 mA constant draw seems very high to me, I would expect something about 30mA. And the 3A draw is off the charts. I have no doubt that this parasitic draw is the cause of my dead battery.

Any ideas? I have researched this and other forums and have come across postings about the HFL, door locks, tailgate lock, and the AC relays. The TSB about the HFL does not appear to apply to '07, and I am not having any issues with the locks. Is there an easy way to confirm or eliminate the AC relay as the culprit?
Does your horn/alarm start to go off when you placed the multi-meter between the ground cable and the negative terminal of the battery? Im trying to find the battery drain.. but I'm not sure if I am doing it correctly.
 

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Make sure you have a relatively high current multimeter (one that can handle at least 5 amps DC. Disconnect the negative cable from the battery, and connect the multimeter between the ground cable and the negative terminal.

It's been quite a while since I did this, but I don't remember anything about the horn going off. Make sure the doors are closed and everything is off when you do this.
 

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Make sure you have a relatively high current multimeter (one that can handle at least 5 amps DC. Disconnect the negative cable from the battery, and connect the multimeter between the ground cable and the negative terminal.

It's been quite a while since I did this, but I don't remember anything about the horn going off. Make sure the doors are closed and everything is off when you do this.
I had the multimeter (MM) set to 10 AMPS then connected as series (as described as above) and the horn started to go off. MM spiked at like 15 or something....

What i did was ran a second wire from battery (-) terminal to the (-) cable. Turned off the blowing horn once connected. Then placed the the MM in place and removed the second wire.

Was hoping that the second wire wasn't needed. :( But it worked. Thank you! I hope this helps someone else that is doing this.
 

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I got the source figured out: it is the radio circuit. I pulled the 10A fuse for the radio, and the current draw dropped to about 15 mA. Before I pulled the fuse, I could hear some mechanical noises from inside the radio every time the current draw jumped up to 3A. The noise was kind of like the changer was trying to change disks. Does the radio circuit also control the HFL? I couldn't find a fuse marked "HFL" or anything similar.

Has anyone had a similar problem with their radio?
I believe my 04 MDX has a normal draw from the radio. When I pulled the "radio" fuse and measured the current, my meter read ~700mA which I assume includes the radio and amplifiers too. When I drained my battery recently I had the radio on and the blower on low. And I wasn't listening to loud music. So I still have a hard time believing the radio/amp and blower on low for 45 min would drain the battery. After I jumped the car, I went to check the battery at auto parts store. They measured 12.7V and 550A of current, a good battery. I don't get it.
 

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I had the same problem with my battery and someone in this forum suggested that I disconnect the bluetooth in the console. It took me about 5 minutes and the battery problem has not happened again. Seems that the bluetooth drains the battery quickly.
 

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I have the same problem with my Acura 2007 MDXthanks to the dealer that sold me a new battery for 170 a month and a half later I am with the same problem and I am very dissatisfied now they say it's the hands free link
 

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selling me a new hands free link for $440 installed or disconnect the Bluetooth HandsFreeLink 440 when I believe the problem with all along the hands free link so thanks Acura this should be a recallseeing that I am NOT the only one with this problem
 

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I Just Dont Understand

Okay, I've read all the way through this thread and am not real clear where I start testing!

My 07 MDX has started this dead battery thing roughly 2 weeks ago. Its very sporadic meaning sometimes it drains over night, sometimes is takes it days. I've also in the past experienced the DVD player making some crazy noise after I shut the car off. Now that is very rare...every 3 months maybe? I'll push a second cd in slightly and it makes it quit. Not sure if that's related but wanted to throw that info out there.

Battery is testing good at O'Reilly as well as the alternator. Battery is an Acura batt with the 100 month warranty and purchased 7/10 (there's a sticker) however I'm second owner of the car so dealer won't replace...which it tests good so I'm not too stressed about that. I just can't make it make sense. So, something is draining my car while its at rest right? Is the car stared and running when I do these tests on the fuses? Will someone please walk me step by step. I will be having my father assist me but I have to go to him with what I know and I need to do. This site has always helped and steered me right. I'm forever grateful for you guys/gals.
Thanks for your time everyone

Edit...HFL works just fine. No issue there. Had key in aux for less than 5 minutes today and now car won't start. Could it be just a batt? But I don't understand why it would test fine at O'Reilly. Also, have had the battery on charger all night last weekend and already dead so I really wanna believe its a batt but O'Reilly tells me differently. Any help I would appreciate!
 

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I'm experiencing same problem. Started with not starting Sunday morning before a long trip my wife took, jumped it, it runs fine while started. Five plus hours of driving would have charged battery, but did not start next morning but did in a couple of gas/food stops.

Then, Monday after jump start in morning, had a two hour meeting, did not start, did not start each time engine is turned off.

I disconnected the HFL(hands free link) in center console as it needs replacing because it stopped working last month, dealer quoted price, but we thought we could get by with headset bluetooth for now.

So now I need to start checking voltage to various components? Audio CD was doing the cycle through searching for discs when car was turned off and unable to start due to low power.

I'm taking the battery in to get it load tested, as quick test from Les Schwab, local tire dealer said battery tested fine, but I'm guessing that was not the best way to determine battery health

I will pass on info as I get it. I'm starting with HFL, radio, starter, ??? in that order as it seems from forum research those are possible culprits.
 

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I had the same problem with my battery and someone in this forum suggested that I disconnect the bluetooth in the console. It took me about 5 minutes and the battery problem has not happened again. Seems that the bluetooth drains the battery quickly.
How did you disconnect this? Having the same problem and want to fix this on my own.
 

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Okay, I've read all the way through this thread and am not real clear where I start testing!

My 07 MDX has started this dead battery thing roughly 2 weeks ago. Its very sporadic meaning sometimes it drains over night, sometimes is takes it days. I've also in the past experienced the DVD player making some crazy noise after I shut the car off. Now that is very rare...every 3 months maybe? I'll push a second cd in slightly and it makes it quit. Not sure if that's related but wanted to throw that info out there.

Battery is testing good at O'Reilly as well as the alternator. Battery is an Acura batt with the 100 month warranty and purchased 7/10 (there's a sticker) however I'm second owner of the car so dealer won't replace...which it tests good so I'm not too stressed about that. I just can't make it make sense. So, something is draining my car while its at rest right? Is the car stared and running when I do these tests on the fuses? Will someone please walk me step by step. I will be having my father assist me but I have to go to him with what I know and I need to do. This site has always helped and steered me right. I'm forever grateful for you guys/gals.
Thanks for your time everyone

Edit...HFL works just fine. No issue there. Had key in aux for less than 5 minutes today and now car won't start. Could it be just a batt? But I don't understand why it would test fine at O'Reilly. Also, have had the battery on charger all night last weekend and already dead so I really wanna believe its a batt but O'Reilly tells me differently. Any help I would appreciate!
First step is to connect the multimeter (10A min capacity) in series to the battery. You may need to have a parallel jumper as described above to avoid ever having the battery disconnected and prevent alarm sounding. MM set to measure 10A or more.

Once MM is hooked up, use the fuse box diagram and remove a fuse from fuse box, observe amperage flow (presumably high), and see if amperage flow is reduced substantially. If yes, you've found the circuit causing the battery drainage. If no, replace fuse and move to next fuse circuit. Repeat until source of drainage is found.

good luck
 
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