Ok so I started having my first issues with my Monte last week. It's a 2002 SS. First I noticed my gauge cluster will reset itself while driving. All of the idiot lights come on and all of the gauges reset. The car never stalls and nothing else shuts off. The issue started right after I got my onstar upgraded. I don't know if that could even be related to this or not. Is this early signs of a bad BCM? Also I noticed that my driver information center never gets the amount of fuel used correct. It is always a gallon or two under what the gas pump says I put in. This is just a minor annoyance though. The gauge cluster worries me the most. So any one have these issues or have any suggestions? Any input is greatly appreciated. Thanks!

 

Sounds to me that the BCM could be failing!

 

You need to purchase a BCM from the dealer or an outside source and have your local Chevy dealer program it for your vehicle.If you install it yourself under your dash on the drivers side near the brake pedal and you dont have it programed, your car wont start! Its aprox a $235 dealer priced part unless you have connections at the dealers parts dept and an hours worth of labor time to install and program it. As far as the DIC is concerned...those things are never really accurate.....i also have a 2002 Monte Pace car and when i fill up...there is always a few gallon difference between what it shows and what the gas station pump shows...its usually shows aprox 2 to 3 gallons less than what the pump shows so dont worry about it.

 

Same on my 02 SS with the gallons used about 2-3 gals off also !

 

So it sounds like the fuel used issue is "normal" for these cars. I can live with that. But the guage cluster still scares me. I can't afford to replace the BCM right now and it sounds like from what I read that is what the problem is. Maybe I will get lucky and it will just be a loose connector or something.......Could anything else cause the cluster to reset while driving? If it is the BCM I am just going to wait until it starts doing other weird things or becomes totally "posessed". I can live with resetting guages I guess. It doesn't happen very often. Thanks for all the input so far!

 

Well I think the possession has begun Tonight while driving home my headlights started turning on and off by themselves at random intervals. It only lasted a couple of seconds each time but was scary because I could not see where I was going. I figured out that so far it only happens on high beams it hasnt done it with low beams yet. Everything else stayed on even the dash lights and parking lights. The weird thing is I never had any issues in the 10 months I have owned the car until a week after I got the onstar upgraded to digital at the dealer. The problems started not even a week later. I don't know if that is just coincidence or not. I am stressed out at this point because I do not have the money for this and now I can't even trust my car to be reliable. From what I have read they can do crazy things when the BCM goes. So does anybody have any suggestions besides a BCM? I'm still trying to remain hopeful but it is prob the BCM. Thanks for listening to my rant.

 

You can try looking at all of your grounds, or go to the dealership and find out exactly what they did for the onstar swap, and see if they crossed a wire, or loosened anything.

I would tell them you started having these problems right after the install and you want to know what they did

 

MonteMan92....The only suggestion i can make is to go back to the dealer which installed your new onstar...You can tell them that these strange problems started to occur after the install and you want your car checked out to see if the install caused these issues but i personally dont think so but it will be worth a try where you will not be charged for the onstar diagnostic. As the BCM begins to fail....other issues will develope in time...your doors wont lock or unlock using your remote....your interior lights will not go on or off at times...your headlight delay at night wont work...your CD/Cassette deck will loose memory...your Montes alarm wont arm or disarm with the remote....your dash lights as well as the others lights on your car will begin to flicker while driving....your bright back up lights will blink on and off when your backing up...Shall i go on?? These are the issues of a failing BCM...when it fails totally....you wont be able to start your car...it will be dead! Maybe you should reach a little deeper into your pocket and purchase another BCM...have it installed and programmed at the chevy dealership and end your stress and this way you can put your trust back into your Monte Carlo and wait for the next issue to start and for sure it will....i have experience in that area with my GM product...the infamous Monte Carlo SS pace car issues.......lol.....Good Luck!

 

Thanks for the input guys. I am going to stop by the dealer and tell them none of these issues happened before the onstar upgrade and they started immediately after it was done. But I agree it is highly likely it is the BCM. I am going to have to dig up money some how. It is going to be hard because I am a poor college student that can barely afford gas at this point. But anyway I am sure it will all work out. I just want my baby healthy again! I don't like seeing her sick. I agree that GM cars seem to definitely have there fair share of problems. We also own a 2000 Monte SS that the transmission is terrible in. It jerks like a manual and shifts crazy hard...so hard the dash shakes. It only has 84,000 miles and they have been very well taken care of miles. Thank god mine isn't that sick. It could always be worse I guess. Monte's are awesome cars but very "needy". Thanks again for the input guys!

 

My Monty isnt needy atall...he volunteers for road trips and doesnt complain- unless we go on a dirt road then he gets pissed! I just got done washing, clay-baring and waxing him and hes taking a snooze in the garage atm....

But yours sounds like u have some electrical issues... like the other poster said, try to find out what was done on the car at the dealer, but do not expect them to not find a way to charge you for something or another...
I bet you have a loose connection at the bcm