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Discussion Starter #1
Hello! During the winter or when it is really cold out, I let my 2007 Pontiac G6 sit over night and the next day it is dead. I had the battery tested and it was good (year old) and also had the alternator tested which was also good. Now that the weather is better I've tested all the fuses and found that Fuse #20 Body Control Module stays on when the car is off and is the only one drawing power from the battery. I would like to know what I should do next to continue the diagnoses? The car runs fine but my battery shouldn't die over one night. Thanks in advanced for any suggestions this problem has been bugging me for a while.
 

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Its normal for the BCM to draw a small amount of current at key off (under 50mA). It never fully goes to sleep. I suspect your real issue is elsewhere. Stuck relays are often culprits.

Youtube has a lot of how-tos on finding a parasitic drain.
 

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Hook up your AMP Meter this way:


Once connected and set to AMPS you can see how much current is being drawn from the battery, All this while the key is off and not in the ignition.
Now that you know how many amps is being drawn you can start pulling and replacing fuses one by one. With each pull watch your meter, See which fuse brings that number way down. That is likely the circuit that's stuck pulling current.

Once you figure out which circuit you can dive into troubleshooting it to find the problem.

Keep in mind the G6 has 3 fuse boxes, Under the hood. In the passenger foot well. And in the trunk.

Good luck!
 

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Discussion Starter #6
Ok so I need to test from the positive cable to positive terminal in the battery? Before I did a light test from the negative cable to the negative terminal to determine what fuse it was so I hooked up a volt meter, set it to 20 V DC, and it was reading 12.25. Am I suppose to hook it up to the positive and get the reading?
 

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you should be reading in current, (amps) and it should be connected in series, so all the cars power must go through your meter. This way you can see how much current your pulling, Volts makes no difference in this case. it's all about current draw.
Here's Eric the Car Guy with a nice video to help you with this. Personally I really think this is the perfect video to show you what to do.

 

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Discussion Starter #8
Alright thanks for the support and video.. I'll get back to you guys tomorrow on how many amps it pulling and see if its fuse #20 thats the problem.
 

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Discussion Starter #9
I did the amp test and its reading 30mamps. The car only doesnt start when its below 15 degrees fareheniet so im wondering if i would have to wait until its cold out again for me to be able to test the amps for the connection? If not what would u guys suggest i do next to
Test it? Could it be the starter?
 

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If that's the drain at the neg battery terminal (per Eric's video) then you don't have a parasitic drain.

Below 15F: can you hear anything from the starter?
 

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Discussion Starter #11
Not sure... The next morning after it being really cold out, when i try to start my car all the lights flicker and make a clicking noise and the car barely turns over like it doesn't have enough juice to power it. I think im gonna have to wait until next winter until its cold out to run more tests unless you guys have any other suggestions or tests I could run?
 

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Discussion Starter #13
The battery i have now its almost 2 years old. Its a ProStart battery from Pepboys. I'm trying to find some specs on it now but no coming up with anything. I brought it to pep boys this past winter when it was happening and had it tested. They said the battery was fine and so was the alternator.
 

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Check your grounds everywhere, body and engine... maybe it's just loose or dirty enough to where you need a good push of amps to get it goin...
 

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Discussion Starter #15
Alright I check the grounds and made sure they were tight and not corroded. Also, in the morning when I put my car in reverse, it hesitates when i give it gas like there not enough power? Any suggestions as to maybe this could be cause the battery to drain or what I should check next?
 

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CD- changer draining the battery

Hello everyone - Troubleshooting a "no start" problem on a 2006 G6 -- if she sat more than a day or two, click and no start. Dome lights came on, battery voltage about 12.3vDC. Started every time with jumper cables. Battery was less than 2 years old, came with a 3 year warranty, so they gave me replacement battery. That wasn't it. Read this thread, started looking for parasitic current -- draw with the car off was 1.6 to 2.1 amps! Started pulling fuses, #20 -- the IBCM1 was it. Then it lead to the radio -- turned out it was the CD changer. One of the CD's was broken inside, must have been trying to eject. Removed the CD changer, reinstalled the radio, now the off-state draw is 160mA, and the car starts every time, battery voltage 12.5 to 12.6. I also checked the "door ajar" switches -- another post said they can fool the BCM, make it stay on all the time. They all seemed to work fine -- turned on the dome light and set the message on the radio.
160mA seems high to me, but it works -- I was expecting 25-50mA.
 

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160mA seems high to me, but it works -- I was expecting 25-50mA.
You may not be waiting long enough. I've found it can take several minutes for everything to settle down - for the various computers to all get to standby mode - and the quiescent current to drop to its minimum level.

I would expect a little lower than 25-50mA ; I'm thinking 10-15mA for the lowest draw.

Regarding the CD changer, it's not clear - were you able to re-install that? I would expect it to be OK with the broken CD removed.

BTW, good job diagnosing this.

Doug

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