Honda Hands Free Bluetooth Module drains Battery - Page 1
Forum section: electronics / repair

author: maggo
author_rank: Newbie
timestamp: November 28, 2017, 11:12:57 pm
content: Hi everyone. I'm having trouble with my bluetooth hands free telephone unit in my car (Honda Accord 2006)It has been unplugged for quite a while now, because it has started to drain my battery quite badly.I haven't measured it yet, but this seems to be a pretty common problem with this module after around 6-8 years.Mine failed after about 9-10 years, but still failed. When disconnecting it, I recocnised that the module was pretty hot, although the car was not turned on and the module should thus not be turned on either. I found several other honda owners with the same problem (Accords, Civics, CR-Vs... - production date between 2003 and 2008). All the modules look roughly the same, despite of different mounting points of the case.In one video on youtube the module hat a constant current of 0.21A ()Some people seemed to have had success repairing this module by reflowing the whole thing.My problem is, that I don't have any possibilities to reflow.I'm not completely sure which component causes the problem. When I remember correctly the top cover of the module was hot when I unplugged it. So I assume the current was drawn by the smaller PCB which is mounted on top. This also seems to the one where the processor is mounted.I hope I can find some help here, but like I already found out that this is THE place to look for professionals.I added some pictures and as I am new here I hope that I'll get some advice on what to check.Are there any components likely to fail after a certain time of heating up and cooling down? Is it more likely a bad solder joint due to heating up and cooling down, or vibration from driving around?I'd be very happy about any kind of advice.Thanks in advance,Marko

author: james_s
author_rank: Super Contributor
timestamp: November 29, 2017, 01:37:12 am
content: You might have a leaky (electrically speaking) capacitor causing excessive draw, or the device may not be going into standby mode.If it were my car I'd just throw away the bluetooth gadget, I've been rear ended multiple times by people who thought they could multitask and drive while talking on the phone. Despite the proliferation of hands free devices multiple studies have shown that it's the conversation that's distracting, not holding the phone in your hand. If it were up to me I'd ban any sort of mobile device use in a moving vehicle.

author: maggo
author_rank: Newbie
timestamp: November 29, 2017, 09:12:54 am
content: Hi. Thanks for your answer. Yeah I know that staying focused while driving is very important. But I rather keep my hands on the steering wheel than having to tap something on the phone when receiving an important call.The most important contacts are stored in the cars hands free and I can call them via voice control. All buttons to start or answer calls are on the steering wheel.It's not like I'm on the phone all the time.The other thing is that with this device removed other voice commands also don't work.Regardless of any concerns wether being "on the phone" while driving is safe or not, I'm interested in solving this problem technically. And I think the issue might be that the device does not go into sleep mode.I was already thinking about installing a switch or something to turn it on and off manually...but then forgetting to turn it off would drain my battery again.

author: Cyberdragon
author_rank: Super Contributor
timestamp: November 29, 2017, 04:36:58 pm
content: Check the caps first. Does the bluetooth not work at all or is it just stuck on?

author: maggo
author_rank: Newbie
timestamp: November 29, 2017, 05:43:47 pm
content: The device worked as it should when I unplugged it. It just had that annoying extra feature of sucking my battery dry.

author: Armadillo
author_rank: Super Contributor
timestamp: November 29, 2017, 06:19:35 pm
content: Hi;Are you sure the module is draining your car battery dead or other thing is draining your car battery dead like a defective close switch of some cabinet lights for example.And could you take the module out from your car and test the quiescent current draw of the device instead?What is the current now? 0.21A?Also take one lead out from the battery of your car and put in series to your current meter and check the current draw without the module [close all doors etc].

author: kripton2035
author_rank: Super Contributor
timestamp: November 29, 2017, 08:07:29 pm
content: best thing would be to rent a thermal camera to see where the heat comes from. it should help to locate the defective component.

author: maggo
author_rank: Newbie
timestamp: November 29, 2017, 08:35:24 pm
content: Haven't had problems with the battery since I unplugged the device. With the device my battery died from one day to the other. Now I can leave my car for at least one week without moving it.I sure can measure the draw, but that means I have to rip apart my interior again. Which I actually don't want to do when it is cold outside because of the risk of breaking clips that get brittle out in the cold...

author: Armadillo
author_rank: Super Contributor
timestamp: November 29, 2017, 09:31:52 pm
content: Quote from: maggo on November 29, 2017, 08:35:24 pmFrom the draw, then you can guesstimate which portion of the circuit is at fault and to what magnitude you are looking at.Why don't you take the power after the distribution relays? Car off, module off, car started, module ON.? Take the power after the cigarette lighter fuse for example.Only the security sentry system takes power from the battery and some emergency lighting.

author: james_s
author_rank: Super Contributor
timestamp: November 29, 2017, 11:56:00 pm
content: First thing I would do is measure current going into the module, and compare with the car on and off, I would expect the current draw to drop with the car off. That said, I'm surprised such a small device can consume enough current to drain the battery so quickly even with it on all the time.

author: Paull Karll
author_rank: Newbie
timestamp: December 12, 2017, 10:54:45 pm
content: My AVMAP 6 APRS does draw down my battery while in standby mode. Todays cars and trucks are pretty close in spec'ing how big a battery compared to how much juice your electronics need. It can be as simple as a little here and a little there that doesn't get fully replaced. My AVMAP has a soft power switch & a hard one. Now that I switch off the hard switch, I no longer have a drained aux. battery.