Electrical gremlins

COBRA617

Member
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2008 Mazda CX-9 GT AWD
Hi all,
I posted earlier about some weird things happening with my advanced keys. At the same time other weird things have cropped up.

Recap- The buttons on my advanced keys no longer lock/unlock the car (I have 3 remotes and none work). Having the key close to the door handle and pressing the black button on the door handle doesn't work either. If I have the advanced keys close to the handle and I hit the black button, I get the chirps like you get to warn you that you are walking away with they key but nothing happens. It doesn't chirp if I press the button on the handle without the key on me. So it is able to somehow know that the key is close. I need to slide out the physical key out of the advanced key and use that. Strangely enough I can start the car normally (obviously as long as the advanced key is in range)

At the same exact time that above problem started, my TPMS light turns on. Well I should say, sometimes it flashes and sometimes it turns off. But usually it is on. All of my tires are at 35psi cold. If this is a bad sensor, is there a way to find out which wheel is showing low?

2 days after the above problems started, I had the car unlocked and opened the rear hatch. The car alarm goes off. I didn't know how to turn it off. I thought maybe starting the car would do it. Get this......the car started.....with the alarm still going off. I then put the physical key into the ignition and the alarm stopped. It may have been coincidence or this may be how to turn it off....I'll need to look this up.

My wife mentioned to me that a few days ago the vehicle wouldn't start. She had to turn the ignition on/off 2 times before it would start.

I have no idea how to diagnose/address these issues. I am considering unplugging the battery but that isn't giving me the warm/fuzzies. The sounds more like a desperation move on my part.

I found how to get into the diagnostic test (I have NAV). There is an entry for remote control test. In that test, it asks to press the remote control buttons. I am assuming that this is for the advanced key. Pressing the buttons shows the light on the remote light up, but the car doesn't see anything.

Thanks,
 
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I stumbled across people having electrical issues and they point to the BCM (body control module) getting wet due to clogged sunroof drains. I went up to the sunroof to look and I see a tube inside the sunroof area that goes towards the windshield, but I don't really see an opening. There is a tiny sliver that looks like the opening. I blew some compressed air into it.

I wish there was a way to verify 100%. I don't want to buy this part only to find out it isn't the issue so then I threw away $300. (Although so far all signs point to it). Luckily, I found that my module (with the factory alarm) is a little over $100 cheaper than the module without the alarm. I might hold off and wait on one to show up on eBay.

A follow up question....If I buy a BCM, is this a simple swap out or do I have to have the dealer program it? I went and looked at the unit and it is pretty easy to get to.
 
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Can't answer the installation questions, but I had TPMS sensors go off and my door remotes stopped working completely, it was a BCM. I'd really look at it being the BCM.
 
Thanks jlanger,
Did you end up taking it to the dealer for repair? If so, did you happen to recall what it cost?
I called a dealership and they said the BCM needs to be programmed and they want $115 (not bad actually). They want $457 for the BCM. I have found it online for $263. I am worried that if I buy the BCM myself that they will balk at programming it.

So back of the envelope math, if I go to the dealer, it will cost me $300 more than if I can buy the part and have them program it. Hmmmm.....for $300 it might not be worth the aggravation.
 
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Thanks jlanger,
Did you end up taking it to the dealer for repair? If so, did you happen to recall what it cost?
I called a dealership and they said the BCM needs to be programmed and they want $115 (not bad actually). They want $457 for the BCM. I have found it online for $263. I am worried that if I buy the BCM myself that they will balk at programming it.

So back of the envelope math, if I go to the dealer, it will cost me $300 more than if I can buy the part and have them program it. Hmmmm.....for $300 it might not be worth the aggravation.


It was fixed under warranty so I didn't get a cost. Sorry!
 
For archival reasons....

I took it to the dealer to replace and program the BCM and that did the trick.

Thanks.
 
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