: Electrical technical help, battery discharge....

04-01-11, 10:29 PM
I have a problem that has been kicking me around. I am not a slouch electrically but this one is really strange and I need some suggestions....
1. Battery runs down to a no start condition in about 14 hrs. First started one day after no significant changes had been made.
2. Have gotten the BCM reprogrammed with the updated TSB firmware, condiitions remained the same.
3. Have removed all Electrical wiring changes I have made and disabled every non factory accessory, conditions remained the same.
4. Have troubleshot this thing ad nauseu with the following observations

A. Normal shutdown procedures of the BCM have been tested with amp meter attached at the various powered sources during RAP. Step down of current draw as RAP deactivates mirrors my other EXT on all circuits except IPC (instrument panel) which is a rediculously small current draw.

B. After RAP is done in about 15-20 minutes the Radio and AMP circuits reduce to essentially zero amps (normal) but after about another 10-20 minutes the radio and amp will re energize to RAP levels i.e. 1.2 amp for AMP and .8 amp for Radio. Radio and amp will be warm to touch and, of course if the battery is left connected this 2 amp draw will kill it in about 10 hours.

C. I put a test light vice amp meter in place of the fuze and the test light will pulse in brightness at both Radio and amp locations and VERY dimly pulse at the IPC circuit. My amp meter stays steady. I use a blown fuze for both the light and amp meter.

D. If I disconnect the amp or radio at their respective power connectors their respective draw disappears but each is independent of each other. It also means to me that wiring to the amp and radio is not defective, particularly since RAP and shutdown appears to function correctly.

In my attempts to narrow this down I have come to the conclusion that something is turning the amp and radio back on....I have considered the VCIM,
chimes, door, or alarm circuits may be the culprits (of course no DTC's are set).

Can anyone provide some input/ideas that I might think about or pursue...I am really tired of chasing this issue.

It is on an 2007 EXT but that is probably not relevant to the problem. There are no other current draws on the battery except amp and radio plus minimal IPC (which I think is remote door lock receiver). My other EXt goes through essentially the same RAP shutdown but does not power back up. That is what is so strange....it almost seems timed on the 2007.....I thought I had it fixed because after the programming everything appeared normal (for my testing methods anyway) and yet the next day it was dead.....When I would test it those two would be drawing current, so i would watch the RAP sequence again see it operating normally just to find the battery dead again the next day. Usually with either vehicle if you mess with the power after RAP by removing the fuze the item in question would power up so it was hard to establish a repeatable baseline unless you considered a dead battery repeatable. It was when I had the test light inserted and had seen it go out after Rap and then went back in the house and several hours later (night) looked out the window to see the light pulsing that I finally discovered that the radio and amp circuits were reactivating. I then sat there for about 20 minutes watching the ampmeter after all current flow had stopped and saw the amp and radio restart. The pulsing when using a test light makes me think of door chimes or an alarm condition but that may not be pertinent because it is the power input that is varying not the volume output. Hood alarm is not relevant because I physically trip the latch assembly to the closed and latched position so it does not send an open/unlatched hood signal to the BCM. I do the same for the doors which I know is effective because the steps retract.

Again any fresh ideas would be welcome.

04-02-11, 12:51 AM
It's the VCIM....Onstar, to assist in emergencies or theft or just simply Big Brother....I installed 2 batteries to " mitigate " the issue but will still disconnect my batteries on vacations of 5-14 days....one day I will remove each fuse one by one and check the battery amps to confirm the culprit, once discovered will research options to resolve

04-02-11, 02:20 AM
It's the VCIM....Onstar, to assist in emergencies or theft or just simply Big Brother....I installed 2 batteries to " mitigate " the issue but will still disconnect my batteries on vacations of 5-14 days....one day I will remove each fuse one by one and check the battery amps to confirm the culprit, once discovered will research options to resolve

One vote for VCIM which I also suspect since I sold my new blue tooth VCIM
to another club member and that would be my luck. That's my next disconnect. Getting tired of running around with my center console area all apart. At least it is moderately easy to get to in that state. And for those who follow the Platinum headlight install....I actually heard the fans in the headlights shut down after RAP....verifying that the logic for the fans is internal to the LED headlight which was a major concern for me but not related to this problem.

04-02-11, 04:46 AM
Try swapping the VCIM with your '08 truck? I know it won't communicate with OnStar properly, but it would be an interesting test to see what happens if the VCIMs are swapped, or if the VCIM is just disconnected altogether.

Thanks for the info on the LED headlight fans.

04-02-11, 10:46 AM
I guess I could put the original non bluetooth VCIM back in the 2007. Can't do anything to the 2008 because it is supposed to be gone next week for the V coupe. GM called me yesterday and said I would have the documents Monday. The V is at the dealer and financing is arranged so it should be just an inspect, sign, trade titles, and drive away. I am excited but I will lose my stock reference vehicle to verify things with. Not a big loss considering the replacement. Got my "V COUPE" license plate reserved....if the trade doesn't go through I guess I will put it on the 2008 as a wishful thinking thing. Will let you know what I find out with the VCIM.

04-03-11, 08:27 AM
My vote would also be for the VCIM. I've had a couple or radios causing battery drains, but not too many. If it's the VCIM, I should have a bluetooth one here, should you need it.

04-03-11, 10:33 PM
Well its not the VCIM. Switched back to the original VCIM....made the mistake of trying to start it without VCIM connected...vehicle went into the alarm condition/locked me out and refused to start....An hour later with the original VCIM installed got it cleared from alarm condition and started....Same scenario...proper shutdown i.e. radio and amp turned off after about 10 min and no current drawn...about 30 minutes later the radio and amp circuits magically reactivate by themselves to about 2 amp draw total without any other changes ....Can only do one circuit current test at a time so did it twice and both amp and radio re-energize...Can't tell which is first though. I do have a defective XM receiver so I leave it disconnected. It is now beginning to look like an alarm condition or door lock receiver activating but no locking/unlocking takes place at that time. Time elapsed before re-energizing seems pretty consistent.

Does anyone know who I can contact that is knowledgeable in the theoretical operation of these vehicles?...My experience is that most dealership service people know less about the actual workings of the circuits than I do but they do have the advantage of the test equipment....no codes and they are lost. The Helms books I have are geared mostly towards actions to take for DTC's that are generated. I have been thinking of putting an O scope on the data bus and seeing if there is coinciding data being generated at the time they reenergize.

04-04-11, 12:42 AM
This probably won't be much help, but I've noticed that even long after the vehicle ignition is shut down, you can press the function button on the dash and get the odometer to display, or press one of the knobs on the radio and get the time to display. Is it possible that these are the reasons why current draw resumes to these two devices? Of course, I don't know if it's necessary for THAT MUCH current to be pulled for the radio just to stand by for a button press... and I also don't know if opening a door re-activates these circuits (I've never stayed in the car long enough after RAP ends to test that).

04-04-11, 01:10 AM
That's good to know...anything that remains potentially activated or in standby is. I will try it. Something is definitely activating the radio/amp circuits. Amp circuits stay semi active for chimes etc after RAP. According to the brief theory provided in the Helm manuals, the amp circuitry is the last to fully deactivate. It could be a bad capacitor in either that as it discharges creates activation conditions. If I have time I will change amps between the 2008 and 2007 and see if that changes things. IPC should be the circuitry that provides the info for that display...maybe there is an IPC problem even though that discharge is small it could trigger Amp and Radio reactivation.

04-04-11, 07:08 AM
When I would leave my 2008 ESV sit in the garage for a week the battery would go dead.

I installed 2 batteries and that helped.

Whenever it sits in the garage for a few days I always put a trickle charger on it because I don't trust it.

04-04-11, 07:39 AM
With my first 2007 I had batteries issues from day one, I took the truck back and they "updated" the software to prevent the battery run down, three days later my battery was dead, so they gave me a brand new battery, one week later that was dead. So after weeks of looking by mistake I saw the hood open on a Police Tahoe at my local Chevy dealer, and had to have it. I never replaced the "bad" second battery just added another and never had a dead battery issue after that, and I some times leave on of our trucks for up to 3 weeks and they just start, try that with a stock one battery Delco. :) These trucks just seem to need a little more power that GM gives us from the factory. :)

04-04-11, 09:37 PM
hcvone: your battery issue story sounds identical to mine...WOW...from when I purchased the vehicle in 08 it was a nightmare even washing, cleaning or working on the vehicle with the interior lights on....I probably had to boost the battery about a dozen times

04-04-11, 09:44 PM
2007caddy, I had the same problem until I put in 2 Optima batteries.

04-05-11, 09:12 AM
Got two Odyssey batteries on order..Hope they will get here by Friday. But since this a NEW issue that did not happen before and I can watch the problem occur, I am sure there is something wrong. I am intimately aware of the normal battery run down and have encountered it several times myself with the stock 2008 and this 2007. Agree that dual batteries are the way to go for normal use and piece of mind. In this case it would simply extend the time before "no start" conditions are met. A continuous two amp draw would kill a D3 battery in two days. It is the equivalent to leaving your interior lights on all the time. Under normal conditions they seem to draw about .05 amps after complete shutdown and the newer programming is supposed to shut that off as well if the battery goes below a certain level. Still trying to find out what is turning my radio and amp circuits back on at about the 50 minute time from key off and about 30 minutes after RAP has shut down them down to zero. There is no display or DVD sounds from the radio but it will get warm to the touch and the amp will too. When I changed my door panels to 2010 style, there was a difference in the front door wiring which I had to resolve...will research that next and then the alarm system. Hate dragging the O Scope out there but may have too. Still hoping someone can tell me what activity happens at that time frame or what other insidious conditions can generate reactivation of amp and radio.

04-10-11, 04:06 PM
Bump for help....I have confirmed it is the BCM re-activating the Radio(1.8-2 AMPS), AMP (.84 Amps), and IPC (.22 AMPS) circuits independently at about the 9-10 minute mark after key shut off. There must be some parameter off and because of that the BCM feels compelled to reenergize these circuits so that when I get back the battery will be almost dead...The BCM obviously knows that it will get my attention that way and that I might fix it. Anybody know what the BCM is checking at that timeframe? So far it has refused to give me any clues. RAP is performed properly i.e. radio and amp shut down to zero at 30-35 secs and IPC shuts off at about the 2 minute mark.

escalade kidd
04-10-11, 06:15 PM
I had a 2007 Denali that had battery issues , would just be dead for no reason. They tried everything and till the day i returned it on lease it still had the problem. One service manager told me there is a problem with 07's that they do not know what it is. One time I had left a dvd in it and it started playing while the truck was off.

04-11-11, 01:47 AM
It is amazing to look out your window and see the lights of the DVD player, then go out and see it playing a movie...Have had that happen on the 2008. The 2007 is sneaky though....the only way you know the radio and amp is activated is by an amp meter or test light, the screen remains blank and without backlighting. And that is after waiting for the previously off circuit to magically become active. Diabolical.

04-11-11, 02:08 PM
I have taken a stop watch to this thing and the times are consistent but not what I originally posted. Radio, AMP and IPC circuits all reduce to zero right about 30 sec after the drivers door shuts. Radio "display" cuts off as soon as the key is removed And the driver's door is opened which is normal. ALL three reactivate within 9-10 minutes after they went to zero amps. I removed the BCM's fuze AFTER it had turned off the circuits and I get a short activation(30 sec) of the radio at the four minute mark but then the radio shuts back down to zero amps. I think that may be the VCIM doing its thing and then shutting down. BUT at the ten/twenty/sixty minute times the radio had not reactivated. Put the BCM fuze back in and the circuits immediately reenergized and stayed on. So it appears the the BCM is sensing some condition and sending the activation signal to the other circuits...

04-11-11, 08:24 PM
Well, at least there is a fuse you can pull in the mean time until you get it sorted out.

04-11-11, 10:09 PM
Great work....I found this TSB on the net....going to the Dealer on Thursday will inquire

There is a TSB for battery drain on 07+ GM trucks/SUVs.
Needs a BCM/RAP module reflash with the Tech 2 machine.

Document ID# 2009971
2007 Chevrolet Silverado - 4WD

Subject: Intermittent Low Battery Voltage, Engine Will Not Crank, Cranks But Will Not Start, Charging System Light On, Service Battery Charging System Message DIsplayed, DTC B1405, B1516 Set (Reprogram BCM) #06-06-03-013B - (09/11/2007)

Models: 2007 Cadillac Escalade Models
2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007 GMC Sierra, Yukon Models
1500 and 2500 Series Vehicles Only

This bulletin is being revised to add step 11 to the Additional Diagnostic Tips section. Please discard Corporate Bulletin Number 06-06-03-013A (Section 06 -- Engine/Propulsion System).

Some customers may comment of one or more of the following conditions:
Charging system light on
Service battery charging system message displayed
Intermittent low battery voltage
Vehicle will not crank
Vehicle cranks but will not start

Diagnostic Trouble Codes (DTCs) B1405 and/or B1516 may be set
This condition may be caused by Body Control Module (BCM) calibrations that create a lower battery state of charge than intended in low electrical power usage modes.

Do This: Reprogram the BCM
Don't Do Thiso NOT replace the BCM or battery current sensor.

A revised calibration has been developed to address these conditions. Technicians are to reprogram the BCM using SPS with the latest software available on TIS2WEB. Refer to the Body Control Module Programming and Setup procedure in SI (Document ID# 1741198). As always make sure your Tech 2 is updated with the latest software version.
Additional Diagnostic Tips
Usually if a vehicle will start and then not start in a very short period of time, the condition may be created by a loose or corroded connection. In most situations a battery in a good state of health cannot be drained within minutes without a major and most likely very obvious short. The following items are also possible areas of starting and charging system concerns and should be considered as a part of your diagnosis. For more information refer to the Symptoms -- Engine Electrical diagnostic procedure in SI (Document ID# 1703276).

Verify the battery cable connections. It is possible for the negative or positive terminal connector nut to tighten without making a good electrical connection on the battery terminal. The top of the negative battery post should be slightly above the top of the cable clamp.
Verify the battery condition and state of charge using the Midtronics tester and a VAT40 or equivalent tester. Refer to the following diagnostic procedures in SI for additional information.
Battery Common Causes of Malfunction (Document ID# 1703244)
Battery Inspection/Test (Document (ID# 1703241)
Battery Charging (Document ID# 1703243)

Verify proper operation of the charging system. Refer to the Charging System Test procedure in SI (Document ID# 1703783).
Verify that the vehicle does not have a parasitic battery drain. Refer to the Battery Electrical Drain/Parasitic Load Test procedure in SI (Document ID# 1741191).
Verify that the front and/or rear Heating, Ventilation and Air Conditioning (HVAC) blower motor turns off with the key in the OFF position. If the blower motor stays on, refer to the Blower Motor Always On diagnostic procedure in SI (Document ID# 1701247).
Ask the customer if they use the accessories (Radio, DVD player, etc.) with the key in the ON position but with the engine off. This may contribute to a low battery state of charge and difficulty cranking the engine. If the customer uses their accessories with the engine off ask them to turn the key to the ACC position instead of the ON position.
If the vehicle is equipped with aftermarket accessories, verify that they are not a source of concern. Remove or disable if necessary and retest the vehicle. Refer to the Checking Aftermarket Accessories procedure in SI (Document ID# 816776).
Verify that there are no loose connections at the 175 amp mega fuse.
Verify that the Retained Accessory Power (RAP) system is operating properly. The radio and accessories should shut off once the key is removed from the ignition and the driver's door is opened. For more information refer to the Retained Accessory Power (RAP) Malfunction procedure in SI (Document ID# 1776533).
Refer to the following Bulletins and PIs for additional areas of concern.
A fuel pump relay sticking concern. Refer to Corporate Bulletin number 06-06-03-011B.
An ignition switch concern and a loss of GM LAN data due to an unwanted ground. Refer to Corporate Bulletin 06-08-45-010.
A rear door lock relay sticking concern. Refer to Preliminary Information bulletin PIT3984 (Document ID# 1820437).

Check circuit 1240 (Red/White wire) for a short to ground in the driver side or circuit 1340 (Red/White wire) passenger side "B" pillar area near the seat belt retractor. See Document ID# 1740425 for a copy of the wiring diagram for circuit 1240 that goes to the driver side and circuit 1340 that goes to the passenger side windows.
Caution: Circuit 1240 is protected by a 25 amp circuit breaker (LT DRS) and may be hot to the touch if the circuit is shorted to ground.

Circuit 1340 is protected by a 25 amp circuit breaker (RT Doors) and may be hot to the touch if the circuit is shorted to ground.

Here is another:
Technical Service Bulletins Summary

Model: SILVERADO 1500
Year: 2007

Service Bulletin Number: 060603009
NHTSA Item Number: 10020948
Summary Description:

04-11-11, 10:31 PM
If I'm not mistaken, WK already had the BCM reprogrammed, so I wonder if a new BCM is in order. I sure hope it's not some mystery condition throwing the BCM off rather than the BCM itself, because that could be damn near impossible to track down.

04-12-11, 12:30 AM
Great Info and yes I did have that TSB installed at my own expense. It did not solve the problem but did change the times that circuits were active, hence my revising of the timeline before reactivation. if you haven't had the TSB done STRONGLY recommend it...the changes to the parasitic draw amounts and times are dramatic.

I have officially given up, lacking theoretical/technical information and testing equipment to further analyze it makes it not cost effective time wise. I do not give up easily. I have a BS degree in Computer Information systems and am fully trained in micro miniature electronic repair and theory and this theory started when 8088 processors and 5meg hard drives were considered top of the line. Information (lack of) is the killer here. I would O scope the GM data bus but without charts to read/interpret what I see that is useless. I am not interested in reverse engineering the electronics of this vehicle. I just want to get it fixed!

My Odesssey batteries came in and I will do the Tahoe dual battery mod and take it to the dealer for further analysis. I have found a chart of the BCM outputs and inputs as it relates to the signals felt and sent....I will (TRY) get a dealer to review these with his equipment to see what changes at the 9-10 minute time. If I can't find a dealer that will let me observe and provide input then I will try to look for another dealer until I do. I have most the interior disassembled to get to all the electronics so I would hope the expense will be minimal if they allow me to participate in the process. BTW, who would guess that the VIN is part of the door/window switch mechanisms and if they are changed a reprogramming is required....I put 2010 door panels on my 2007 and they would not work correctly..before I found this out I simply used the 2007 controls on the new door panels.......The previous owner had made and installed custom multispeaker door panels which I did not like.

I am supposed to pick up my V Coupe Thursday and then the 2008 Ext will be gone, so no stock reference vehicle to validate things with. 2007 EXT issues may take a back seat for a while because I will have to thoroughly test the V Coupe. Its not red or a manual so it already has some reservations to overcome. The 2007 EXT is a keeper regardless.

I will update this when new information is found but if anyone knows of a potential source of the problem or a person who knows the intricacy of the circuitry PLEASE let me know. I just hate admitting defeat and don't have any confidence that any dealer in my area has a person knowledgeable in this area.

04-12-11, 01:26 AM
I have replaced my battery sensor module, positive and negative battery cables, front and rear door panel controls, VCIM, alternator, 175Amp fuze, reset fuze box, absolutely without doubt verified it is not my Platinum headlights or circuitry, removed lockpick and Passport, removed underbody lights (electrically), removed West Coast custom 17" rear display, removed headrest dvd palyers, removed CB radio, removed cell phone charger, removed Fosgate subwoofer, removed Cobra inverter, removed HDTV tuner, removed the GM XM radio(it was defective, .5 amp draw at ALL times), removed amped antenna, and the only things left are the MR shocks and circuits and the front camera (disabled by the Lockpick removal) which I have become attached to. All of these things worked fine and after their removal no change was encountered......Most were on relays and prevented from operating at any time except when engine was running. Took them out in preparation for TSB so that there could be no question as to source of problem. Unfortunately, these many changes do open up the possibility that I mucked the wiring somehow but that is highly unlikely because of the triple check and recheck I did trying to find the cause. Also this problem appeared when no accompanying change had been made. All other things had been operating as I expected. No DTC's were found when the TSB was done except an historic out of parameter for suspension reference voltage which turned out to be a bad ground. Since this was a used vehicle there might be some wiring issues generated by the previous owner but I haven't found one yet. My bet at this time is a door or alarm condition triggering the BCM to energize the RAD, IPC, and AMP circuits. Can't reference this with the 2008 because it has the dealer installed shock sensor alarm and two way remote which changes wiring and programming. Warranty is not my concern...I don't care if it is a GM part that failed. I will gladly pay for it's replacement regardless just as long as it fixes the problem....I am not willing to live through paying for guesses by the dealer. But you can imagine how difficult it is for me to get ANY dealer to troubleshoot this issue. It all comes down to: what does the BCM look at at the 9-10 minute mark after shutdown?

Big Windy Ext
04-12-11, 07:48 AM
Geez , I thought my alarm problem on a car I can't remember was a doozie ! The clocks on old cars had a rundown spring , when it needed to rewind points would touch activating a solenoid rewind , fooling the alarm that a door was open . So like "clockwork" my alarm would go off .It probably has a corrupted program that turns on something wrong at the wrong time . I hope you figure it out soon !

04-12-11, 09:04 AM
Thought of the clock too...it is powered off the RAD circuit so took it out and still have prob..I don't think the new clocks use the mechanical winder of the past which were notorious for failing...

I am 99% sure it is not the BCM itself...I have a spare BCM out of a Platinum ESV but it has to be reprogrammed immediately upon replacement, otherwise you don't go anywhere. It WOULD require a few wiring changes as well. Once changed it might not even be able to be analyzed by the dealer because of the VIN specific programming. So that is last resort.

54 hours to "V" day.

04-12-11, 10:32 AM
Enjoy your V when you get it. I'm thinking of getting one very soon.

Sent from Android.

04-13-11, 05:27 AM
Gosh, at this point I'd be so frustrated I'd use my technical skills to just create some electronic switch to cut power to the BCM upon ignition shut down or 10 minutes thereafter. Problem is I don't know what happens when the BCM power is cut (i.e. whether that resets a bunch of stuff).

In other words, if I can't count on GM's design to function properly, AND I can't figure out what's causing it not to work, AND I love the car enough to keep it... it would be time to McGyver up my own solution and move on.

04-14-11, 01:13 AM
Stubbornness has it own virtue. With twin Odessesy batteries I probably can withstand the 3amp draw for 3 days before no start low voltage conditions exist. But I now WANT to know the reason and am willing to endure further pain to find it, if I can find a sympatico dealer to help me with their equipment. I could just put a BCM killer switch in the vehicle but don't want to go through the resetting process everytime.....When my ECM has a chance to adapt to things my gas mileage goes up appreciably. And I am tired of resetting my DIC options. I think this process (power disconnected) has also finally killed my ABS/SEAT belt internal batteries (and my main battery) which will be an additional expense to replace and reprogram. I wish they would just concentrate systems according to its function without making everything so interconnected and constrained by VIN. It makes absolutely no sense to have door panels controls programmed with VINS.

14Hrs to "V" day.

04-14-11, 01:46 AM
Why do you think Chinese Tech IIs are such a huge deal on Ebay right now? GM has everything so locked down and centrally controlled, that owning your very own Tech II, even if it is a Chinese knockoff, gives you AMAZING power over what you can do TO and WITH the car. I am very tempted to have one, but even the knockoffs are 1400.00.

For those who love to have the latest and greatest, and who are consistent GM vehicle owners, it's almost the got to have accessory.

04-14-11, 01:56 AM
You are so right....I can only imagine what it will be like in 3-5 years when weird problems start showing up for various reasons. Time to dust off the Ranchero which will run with no electronics except for the Nascar MSD module.