OnStar Backup Battery 2004 H2

[Olfart]

Started getting a RED light on OnStar. I can get it to turn back to white by pressing the OnStar button, but if truck sits a couple of days then RED comes back on. Called OnStar and they said it might be the backup battery going bad. Has anyone ever replaced this battery or is it something else that the Dealer must get rich doing....ie programming, etc.

[pdsq99f4]

I'm pretty sure your h2 doesn't even have a backup battery. Take it to the dealership to have the code scanned.

[Easy Ed]

Cannot find anything about a battery for OnStar in the 2003 service manual

[Olfart]

Originally Posted by Easy Ed

Cannot find anything about a battery for OnStar in the 2003 service manual

I can't either. but I read somewhere that GM started putting in backup batteries in 2006. My truck is a 2004, but in 2007 GM replaced my OnStar inder warranty to change me over from analog to digital cell phone system. So more than likely my OnStar system is now a 2007 with a backup battery which is used to keep OnStar alive after the 48 hour main power automatic shutoff of power from the Hummer battery to keep the main battery from running down. As long as I run the truck every day it's OK, but if it sits for a couple of days I get the red light on OnStar. Once I have the truck running I can press the OnStar button and the light will go white again and it works OK. I imagine that with a bad backup battery the features like antitheft GPS and remote unlocking won't work if truck is parked for more than 48 hours.
Guess I'll have to give my GM dealer a call, but I hate to hear their cash register going KACHING.

[Easy Ed]

Ah, I see. I did a little digging and did find this http://www.sandyblogs.com/techlink/2...p-battery.html not for the H2 but may give ya a idea what to look for.

The BUB is a non-rechargeable, lithium battery with a lifespan of approximately 4 years and is designed to maintain an open circuit voltage between 16V and 9V throughout this period. This allows the battery to power the basic functions of the VCIM for least one 200-second (5 minute) phone call at the end of the 4 year span, should a main vehicle battery loss occur.

The BUB voltage is checked every ignition cycle. If the BUB fails the check or if the BUB has had current drawn from it, the OnStar LED next to the control buttons changes from green to red and a DTC is set, either B1446 or B1447.

Service Precaution

Do not disconnect the vehicle battery with the ignition key in the run position.

With the ignition key in the Run position, the OnStar module is awake on the data bus.
The OnStar module is also awake after the ignition key is removed, until Reserve Accessory Power (RAP) times out, or the driver door is opened. If the vehicle battery is disconnected with the OnStar module awake, the OnStar module senses a vehicle power failure, as could occur in a crash, and draws current from the BUB. When the vehicle battery is reconnected, the OnStar LED is red and a DTC is set. Because the BUB has had a current drain and there is no way of telling how long the drain was, the BUB must be replaced.

Refer to Accessories in SI for OnStar battery replacement information.

[Olfart]

I guess I'll give OnStar another call and see if I can get hold of a tech person to find a part no for the battery and also where is it located. I read that on several other GM vehicles the battery is under the driver's seat...don't see it there on the H2. If it's inside the actual OnStar unit it will mean pulling at least the center console to get to it... ARGH. Too durn cold outside to mess with it now and I really hate to pay the Chev dealer the big bucks to replace it. They get big bucks just to do a scan and my old scanner only checks engine and tranny codes. As long as I run the truck every day or two...which I usually do...it seems to be OK....for now anyway.
Thanks for the info

[H2 Bill]

Keep us posted as to what you find out! Mine has been doing that for about 6 months now. I called OnStar and they told me that the entire unit needed to be replaced....It works fine except for the red light.