I have a 2009 Corvette convertible 2LT. I had the original battery replaced about a year ago. I didn't drive my car for 3 weeks, and it wouldn't start. I brought the battery into AutoZone, they charged it, and said the battery was bad. I took my Vette into the dealer to check out the battery and do a 30K mile check-up. The dealership has had it for a week and a half now. They said the battery was fine because they were able to start it fine every other day; after resetting the computer and testing it, they said I need to replace the VCIM. They said this would be $918. The worker told me that the VCIM relates to OnStar (which I don't use; I only had it activated during the initial free trial period when I bought the vehicle new). I asked the worker if there is a way just to disconnect OnStar or some other alternative that won't cost me so much. He was saying that the VCIM needs to be replaced. I wanted to get the thoughts of others in this forum. Do you think the VCIM really needs to be replaced, or is it possible the dealership is trying to make an easy grand? Is this something that I could replace easily enough and save $100s?

 

VCIM is GM's fancy name for the ONSTAR box. Others will chime in but I think you can just pull the fuse for it and call it good. So glad I don't have one.

 

First off -- I'd be suspicious of a "Bad VCIM" diagnosis, especially given that you don't use OnStar. Is the dealer saying the "bad" VCIM is causing the starting issues?

You can't just pull the wires on the VCIM box, because its part of the data bus. That being said, if you are not using OnStar or Bluetooth, then the VCIM is nothing but a jumper for the rest of the car's network. (If your car has the bluetooth option, then the VCIM also handles the Bluetooth comms between your car and your cell phone, even without OnStar)

If your C6 doesn't have BT, you can either jumper the network wires in place of the VCIM to keep the network up (bypassing the VCIM completely), or pick up a used C6 VCIM for less than $100 and plug it in. Even if the car *has* BT, you can do this, but you'll lose BT functionality -- that's all. Neither of these options is sanctioned/approved by GM -- that's why the worker didn't tell you about them.

 

You know more than me....can he just pull the Onstar fuse??...will that keep the jumpers intact and allow the car to still start?

 

Depends on what the dealer claims the problem with the VCIM is.

The only problem I can imagine with the VCIM not allowing the car to start would be a physical wire break in the VCIM unit itself. In this case the fuse pull won't work.

If the dealer claims the VCIM is running down the battery, the fuse pull may help, but if that's the case, I thought that was cured with a re-flash, not a replacement.

From the OP's post, it sounds like the dealer is saying the VCIM is *not* preventing the car from starting. "They said the battery was fine because they were able to start it fine every other day".

If AutoZone said the battery was bad, I'd tend to believe them -- auto store battery testers produce a lot of false positives, but their negative results are fairly reliable. A 1 year old battery going bad in a C6 is unusual, but not unheard of.

 

So he could at least start by pulling the fuse...would that be his best starting place?

 

I would go with the suggestion of just buying a new VCM off of EBAY , without Bluetooth they are less than $100.00 and take 5 minutes to install

I am still having a hard time believing that a VCM would stop the car from starting but stranger things have been told on these forums

Dave

 

Short version, VCIM is the car link for ON Star, and contains the Blue tooth module in 2009 and new models.

If you are using blue tooth, then you will need to either replace the module, or pull it apart to see if there is a cold solder joint on the GM Lan bus connectors that is causing a short across the lines.

If you are not using Blue tooth, or tired of the Onstar calling home when you don't have the service to drain the battery, then you can just unplug the VCIM and jump out the Gm lan bus wires through the connector isntead.

 

Thanks for all the responses. The dealership told me that based on their test, the VCIM doesn't stay turned off when the vehicle is turned off. He said that it is supposed to turn off, but since it might come back on periodically, that is causing the battery drain. This was his reasoning of needing to replace the VCIM. Although I don't use OnStar, I do use bluetooth to talk through my cell phone. I'm thinking what I might do is just buy a battery tender and hook that up through my cigarette lighter when I have my C6 parked in the garage. I don't think I should have to do that when I have it parked for only 3 weeks, but that might be my workaround.

Based on your responses, that gives me the confidence that paying the dealership almost $1,000 isn't worth it. My Vette is still in their shop after 2 weeks, and they still haven't responded to me on whether or not there is an easier fix besides replacing the VCIM with a new unit.

I also wonder how the dealership is running their tests. I have my fob set to unlock the door automatically as I walk up to the car (so I don't have to press the unlock button on the fob). I wonder if it's possible that as they are running the test, they have my key with them, and that is causing some of the car's computer programs to run (including the VCIM), giving them a reading that these systems are turning back on when the car is not in use. If that is the case, that testing wouldn't be realistic, considering my key is typically in my house, away from my car.

 

The C6 does NOT have proximity-based "active" unlocking. Unlike earlier generation Corvettes, absolutely nothing happens in a C6 just because you simply walk up to the car.
When the C6 is locked, nothing happens until you press the door pad (or trunk button) -- then and ONLY then does the car check to see if the fob is in range. So you can cross that off your list of suspects.

(and FYI -- there is no "option" to set this "auto unlock" function on or off -- its SOP for all C6's at all times. The only "option" is passive LOCKING of the doors, and I believe that is timer-based, not proximity-based.)

 

This is correct and a commonly misunderstood feature of the car. No one ever needs to push a fob button to unlock the car...it will always unlock when the rubber pad on the door is squeezed or the trunk button by the license plate is pushed, with the fob in range.
Also, if the battery in the car is getting low after three weeks of sitting, this is normal behavior for the C6, especially one with Onstar. If it is expected to leave the car for three weeks, a tender is the solution...simple. Even if the car will start after three weeks, the battery will be significantly below a full charge and this will shorten the life of the battery. Car batteries like to be stored in a fully charged state for the longest life. Even if the battery will still start the car when it is at 50% charge, letting it get down there repeatedly will shorten its' life. Get a tender, use it when the car will sit for more than a few days and enjoy your bluetooth...I'm betting there is nothing wrong with anything Onstar-wise.

Also, it is normal for the Onstar module to be using current all the time...it never shuts down completely because it is always waiting for a signal from the cellphone network to unlock the car. A tender is not a workaround, it is a normal requirement for a car with lots of computer activity. Other cars would be the same except that most cars are driven every day or two...the Corvette is one of the few cars purchased and then allowed to sit for long periods. This is why it's easy to find a used C6 that has only been driven 1,000 miles a year, while it is almost impossible to find a Chevy Tahoe in that same condition.

 

1, Although you don't have a Om star account, the On start module is still calling home one in while and why the on star module is turning the VCIM on.

2. even without On star or the VCIM connected, the car itself is pulling enough power in stand by to drain the battery in about three weeks if the car is left sitting.

There are work around to disconnect the Onstar module without removing the VCIM (but you need both since you are using the on star button for your phone), but if the C6 is left to sit for more than a few days, get it on a battery tender.

As for battery tender, will not go wrong with a Ctek 3300. It's a little more money, but has a desulfate cycle on it to make your battery last even longer.

 

If that was me ...I would remove the OnStar box and blow shoot it with my shotgun 'and get a aftermarket BT.......

 

I'm all for going full "Office Space" on bad electronics.

But the aftermarket BT solutions don't work as well and aren't as well integrated with the C6 as the OEM -- at least the ones I have tried.