First I want to apologize for violating the 45-day rule for an old thread: http://forums.corvetteforum.com/c6-c...post1573212590 I am new to this forum, and ended up here after checking out probably every other forum on the web.

Second I want to thank prs62 for the information he provided about DBS: "GM released the fix for DBS in 2006 with PIC 4188(X) where X is the update letter. My 2005 was re-flashed in Nov. 2006 (PIC 4188B) and I haven't had DBS since." This is the most useful information I have gotten in years; I guess I didn't get the memo.

My 2005 ZR51 M6 has been serviced at several dealers for the DBS problem, but the problem remains. It has 18,000 miles on it and is still under the extended warranty. The quiescent current draw is typically 184 mA when parked (after 15 minutes, hood light removed, in reverse, etc.). Most recently, I paid for "all firmware updates" (not covered by warranty), but I then spoke to the mechanic that did the work and he told me that they only reflash the Drivetrain Computer. So in view of above, I'm concerned that maybe the Body Control Module (BCM) or other related modules have never been reflashed. Could you tell me if there is any way to verify if the BCM firmware has been updated, or if there is any equipment I could buy that would allow me to do this myself (possibly a tuning tool or PC-based appliance?) I would be hugely grateful for your patience and expert assistance.

 

I had a similar/same problem as you with my 05 mn6. Regardless, of what or how I shut the car down there was always the chance it would drain out overnight, even with new battery.

After reading the posts from this thread:

http://forums.corvetteforum.com/c6-c...m-reflash.html

I printed the TSB #07-06-03-001B (rcdlr update) and the other PIC4188E (pcm/ecm update) to the dealer and discussed the issue with him. He accessed the available updates for my car - can't remember if he found another, but found items regarding the above for a battery drain fix.

Flashed the car. It's been flawless since then.

The fellow I went to walked me through the upgrade process as he was accessing the GM website for the upgrades.

(hope this is useful)

 

Yes, this is enormously useful. Thanks very much to you and ChevTech (from 2008) for assembling this detailed information. I will take my car back to the dealer with a printout of your message and TSB. I will hope that they will be as helpful as the dealer service person that assisted you. I'm assuming, by default, that firmware updates can only be done by an authorized Chevy dealer.

 

I have an 05 that I purchased in January and have only driven it a few times (with no problems...knock on wood). I saw my GM VIS report and it looks like it was never updated.

Should I get the update performed anyway? Are there any other advantages (other than DBS) for getting the update done?

Patrick

 

Not 'the answer' you are looking for but it may be useful.
http://www.prioritystart.com/

 

Thanks. Just ordered one yesterday. And I'll wait until I have this before replacing my 3-month old Optima Red Top, now nearly dead after 5 full discharge incidents. And maybe the problem will go away if the BCM is reflashed after I take it to the dealer again - an encounter I'm not looking forward to.

 

Sorry for the dumb question, but what is a GM VIS report? Is this an inspection report you had them do when you bought the car?

I haven't yet had my appointment with the dealer, following the last one for which the bill indicated "perform all cal updates", but they may have only done the DCM. They didn't give me any other paperwork about what was done. I'm hoping that the BCM and maybe other modules haven't actually been reflashed, and that when they are, this will provide the major part of the cure, getting the parasitic current down to the 20-30 ma range which others have reported as typical for the auto trans '05 and all '06 and later models. Even this is high, compared with, say, the 14 ma parasitic draw of my '06 Prius that also has a keyless entry system (and possibly software bugs of its own making headlines recently). Which is why I'm also investing in the device previously recommended by others to avoid killing yet another battery. I'll check in later after I've gotten to the bottom of this.

 

I installed the PriorityStart on my O5. I then had to have the dealer do a scan for a non related problem. When the tech hooked up the scan tool the PriorityStart shut off the battery. The only way I could get it to turn the power back on was by pulling the ground wire from the PriortyStart. Then as soon as the tech tried to hook up again it shut off the power. I ended up removing the PriorityStart and sending it back to be tested. I was told it was working properly and there was a 1 min time delay for opening when the voltage drops below 11.7 VDC. It opened after about .5 sec. when the tech tried to hook up the scan tool.
They sent me a new PriorityStart in a box.
One new PriorityStart in a box For Sale $50.00

 

I'll heed your advise and remove the Priority Start unit before taking it to the dealer again. I'm reluctant to have the work done *again* until, using the local grapevine, I can find a local dealer that will allow me to talk directly to a mechanic that is knowledgeable about this problem for the '05 M6. Until then, it still draws 190mA continuously when parked, so I keep it on a Battery Tender at home, and have a Priority Start to save me from being stranded. Great product - it has saved me several times already.

 

My Chevy dealer's Corvette Tech is one of the best and I not only talk with him I work with him on my Vette when I need work done that I can not do myself. I do not have a scan tool yet and I had a air bag light on. The slight drop in voltage hooking up the scan tool caused the PriorityStart to open. Have you ever had your dealer do a scan on your Corvette with the PriorityStart installed?
I have the battery drain problem down to a minimum by removing relay 46 and doing the proper shut down as well as keeping the software up to date.
I have a new PriorityStart you can have for $50 to put on one of your other cars.

 

I don't need another PS, but strongly recommend this product to other 'vette owners, since even the non-'05M6 models are known to have parasitic drains higher than normal and a dead battery is likely if the vehicle is stored without disconnecting the battery. If it matters, I have a Priority Start-II, which has some improvements over the original PS.

I do have an OBD-II scanner, and no DTCs were present when I last checked. I haven't scanned it since installing the PS, so I'll check that and see if it affects the PS start. I can't imagine how the attachment of the scan tool could cause the PS to disengage, which is supposed to occur only when the battery voltage drops below 11.7 V. Perhaps if the battery voltage was already just above the threshold and the load of activating the diagnostic functions of all the on-board systems pulled the battery voltage slightly below 11.7? A long shot.

I'm sorry, but I'm not familiar with the function performed by Relay 46. Do you permanently disconnect it or just when you park? What is lost by removing it?

 

Relay 46 is for headlight washers that we do not have but puts a load on the system. I junked it. I really never had power problems after I learned what to do on shut down and to keep my 05 on a charger if it is not driven for more then 5-6 days. I desided on the PS just in case.
The battery was well over 12.6 VDC at the time. Considering they sent me a new PS I think the original had a problem.
By the way the only way I could get it to close was by pulling the ground wire. The brake pedal, headlights or electric seat switch would not reconnect. Does your PS reconnect as they say it should?
PS For Sale $50

 

Yes - it needs a pretty substantial load. The cigarette lighter will do it, and it is powered even when all other systems are shut down. Then you only have a short period of time to start the car before it will shut off again since the voltage will be below 11.7.