QUESTION: I have a '03 Chevy Monte Carlo SS 3.8L.I started having issues months ago with just random warning messages in the message center (ie..Security(flashing#, Service Vehicle Soon#. Then my dome light would come on every 3 to 5 minutes while driving. I would turn it off manually, then it would come on again. On the days this issue would happen, the power door locks would stop working too. These 2 problems always occur at the same time. I found that if I push and hold the traction control button down by the shifter lever, I would hear the pwr locks engage and the dome light would quit coming on randomly. Those 2 problems only happen about once a month. Sometimes when starting the car, I have to turn the ignition to start, when nothing happens, I turn it back to off, then turn ignition to on and wait for the dash lights to come on and the self check to start, then turn it the rest of the way to start to actually start the car. Most of these things are just irritations more than anything. But now my "highbeam out" message comes on, my turn signals flash rapidly and very dimly at the same time no matter which direction I switch on. I've replaced all exterior lights #there were 2 marker lights out#. Everything worked fine for a week, then the message is back on and signal lights acting up again. This time, there are no lights burnt out and other than the turn signals flashing oddly and not bright, all lights do come on and work. The only other difference is that instead of daytime lights running a low voltage on my highbeams like they are supposed to, my lowbeam lights come on instead. I've check and replaced fuses. I'm 99% sure it's the BCM causing all my problems. I researched the functions of the BCM and there seems to be a strong focus on the fact that after replacing, it has to be programmed #at a dealer or garage# to the vehicle. I was told by an online "expert" that if I got a working BCM from a car in a junkyard that if that car did not come with the alarm option #checking VIN # to be sure# then I could use it in my car #that does have a factory installed alarm# and not need any programing other than the keyless entry remote I do myself following owner's manual instruction and performing the computer reset #ignition "on" 10mins..off.."on" 10mins..off.."on" 10mins#. But I would not have to go to a dealer or garage to have it programmed to my car. Does this sound correct to you? Thanks in advance for your help.
ANSWER: HI ADAM,YOU ARE CORRECT IN THE FACT THAT THE BCM IS MORE THEN LIKELY THE PROBLEM..I WOULD ONLY GET A NEW BCM FOR THIS CAR AND GET IT FLASHED AT HE DEALER OR GARAGE THAT HAS GM SOFTWARE..
IF YOU GET A USED BCM IT WILL NEED TO BE FLASHED AS WELL...NO WAY AROUND THIS..THE CHANCES OF YOU FINDING THE SAME BCM WITH THE OPTIONS THE SAME ARE VERY RARE..THE USED BCM WILL NOT MATCH THE CARS MILEAGE..IT WILL KNOW THIS RIGHT AWAY...SO GET A NEW BCM PLUG IT IN AT THE SHOP OR DEALER AND HAVE THEM COME OUT IN THE PARKING LOT AND HAVE THEM FLASH IT. [SAVE ON THE LABOR OF INSTALL.] FLASH WILL COST ABOUT $95.00..THE REASON I DO NOT LIKE USED PARTS IS BECAUSE YOU MAY END UP WITH MORE PROBLEMS. JUST NOT WORTH IT..GOOD LUCK TO YOU AND IF YOU NEED MORE HELP GET BACK TO ME,,,TOM....
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QUESTION: Thank you for getting back to me so quickly. I had intended on buying a new BCM anyway since they are only about $55 from local parts stores. I was just trying to get around the programing part since I thought that would be an added cost...BCM + installation + programning. From your reply I'm a little uncertain as to what you meant when you said to have them come to the parking lot and flash it. I know what the flash part meant, but the not the parking lot part. Can I drive up to a dealer, plug in the new BCM to my car ...just letting it hang there in place... then have a service tech come to the car with the scanner and flash it right there? Is that what you meant? That woud certainly cut down the overall cost. I was under the impression that it would require the car being in the bay hooked up to diagnostics or something like that.
HI ADAM,YES THAT IS WHAT I MEANT..PLUG IT IN THE PARKING LOT AND HAVE THEM FLASH IT. ONCE YOU PLUG THE NEW ONE IN, IT WILL NOT START.. JUST LET IT HANG THERE..INSTALL IT BACK WHEN YOU GET HOME..COULD I TALK YOU IN TO GETTING A DELCO UNIT INSTEAD OF AFTERMARKE???? WE HAVE HAD LOTS OF PROBLEMS WITH AFTEMARKET UNITS...GOOD LUCK,,TOM...