Can I replace BCM myself?

[bradnelson]

Im in a bit of a pickle. my 2002 saturn vue has a bad bcm. I bought a new one and about the same time my company closed down. So being out of work im wondering if I could replace the BCM so my car will start, then i could find employment and get the vue fixed up better.

I've been resetting the bcm so the car would start by disconnecting the battery, that worked for about 1 month, but not it wont start anymore.

any thoughts or concerns about me trying to replace it myself?

[fdryer]

Only if the new BCM was already programmed otherwise you bought just the BCM sans specific programming such as mileage and VIN missing, among other essential information needed for complete programming. Saturn is the only place to program what I believe is a blank BCM as they're the only ones with the Techtool II equipment to program BCMs. By chance is the lack of starting from the Passlock security light being on all the time?

If I'm mistaken and you took the precaution to pre-program the replacement BCM, then by all means replace the faulty BCM! Remove the battery negative cable and leave it this way until the BCM is fully mounted and connected properly. The only caution in replacing the faulty one with the new one is carefully avoiding static electricity (the killer of electronic components) by leaving the BCM in the static protective bag on the floor in the Vue before removing it to mount and connect to the wiring harness'. You can dissipate any static charge on your body by simply grasping any metallic part of the Vue's dashboard frame, minimizing squirming around in the seat and generating static, minimize fussing around and simply mounting the BCM and connecting the harness'. There's very little chance of electrostatically blowing a component within the BCM but a little caution reduces the risk.

[bradnelson]

Thanks for the reply.
No, i dont have a passlock light on. My speedometer reads 698,xxx or whatever that code it that says its a bad bcm. I talked to saturn and they agreed it sounded like a bad bcm.

I bought this newer bcm from a company that took it out of a used saturn. they said said they tested it and it worked. so since it was already installed is that a good thing?

ok so if i attempt this, where is the old bcm located? i have yet to reseach how to replace it so i dont even know where its located.. any idea how long it will take to do it myself?

Thanks for all your help!

[fdryer]

Uh, there may be a different odometer reading as well as the VIN from the donor vehicle. I'm not entirely familiar with the Vues as I am with the L300's. the L300's have their BCMs above the glove compartment and I think yours is above the radio. Check the threads using the search function here for the Vues. It takes as long as it takes you to find the BCM location from searching here, members advice, and disconnecting whatever is necessary to access the BCM wherever its located and plugging in the replacement BCM. If you confirm whether its above the radio or elsewhere, then its just a matter of battery disconnection and removing the necessary dash panels to access the BCM. Maybe an hour or so, less if you know your way around the dashboard and all the hidden hardware, more if you don't with skinned knuckles to show for the effort. Sorry if I can't be more specific.

[JDub99SL2]

You can install the BCM yourself but you cannot program it correctly. The BCM needs to be programmed for your vehicles installed options (1 or 2 relay cooling fan system, mileage, fog lights, PDL, etc.). You will also need a scan tool to program the remote key fobs.

Most importantly, the mileage needs to be programmed. Once the mileage is programmed into the BCM, it cannot be changed.

The used BCM you bought will always count up from the mileage it has in memory and the options may or may not match that of your vehicle.

Pay for a new BCM and have it installed and programmed correctly. If the incorrect mileage is the only sign of BCM failure, you can wait until you have the money. Just make note of the actual mileage so when you have it reprogramed it is not that far off of the actual mileage.

Just FYI, your alarm may go off in the middle of the night, random horn honking, lights flashing, no start w/ security light, etc., etc.

Bad BCMs are funny. Anyway, you cannot do it correctly without the correct computer, software or a Tech 2. I would not install a used BCM, if I were you.

Justin

I just remembered that getting access to the Vue's BCM is rather easy (remove window switch bezel, radio trim bezel and radio) but actually detaching the BCM from the car can be a PITA unless you know how. It's still a little bit of a PITA even when you know how). Also, you have no idea if the used BCM is bad. Neither do the people that yanked it.

[mellissam]

Originally Posted by bradnelson

Thanks for the reply.
......I bought this newer bcm from a company that took it out of a used saturn. they said said they tested it and it worked.....

Haha, that's funny. Unless it was a Saturn Dealer, I seriously doubt it.....

[anakin876]

I've had the BCM die in my 2006 Vue twice - fortunately replaced under warranty both times. So I've been posting and reading threads regarding BCMs for a year or so here. There's another thread around here where someone got the dealer to reprogram a BCM for 150 bucks at the dealer - I know you said that you are looking for work at the moment, but maybe that would be in your budget range? This way you can put the replacement in and get it programmed correctly - thus avoiding any bad things that might happen from an incorrectly programmed BCM.

[Jess Lookin]

Ok, is the bcm a dealer only part ? Looks like the wife's Vue needs one.

[fdryer]

Well, you can try shopping around but beware of used ones from new blanks. All used bcm's retain the car mileage and cannot be erased. Only new blanks programmed only from a GM service center can do the replacement perfectly as GM is the only authorized dealer with the proprietary software to use a Tech II to program bcm's. No one else.

Buying used bcm's is a gamble as mileage from this bcm will never be the same as yours. The used one may have more or less mileage than the one it replaces. Very few bought used bcm's with less mileage than the one it replaced.

[Jess Lookin]

Thank you ! I'll just order one from the dealer then.

[CoJames]

My BCM has been getting progressively worse for the last several years, to the point that I think I finally need to replace it. All manner of intermittent weirdness, from wipers, to gauges, to odometer, to lights, to door locks, to no-start and more. Fun.

Anyway, does anyone know if an "GM Original Equipment" BCM from Rock Auto (or other online places) will work?

Local GM dealer in Denver wants $462 + $140 to program it. The online one is $238. Expensive either way, but that's a big difference.

Also, someone a while ago posted that their dealer screwed up several BCMs trying to program it.

Originally Posted by hypnotize83

...they sent it to a Chevy Dealer(Bankston Chevy Fort Worth, TX). It turns out that GM's software is messed up and the dealer had the same issues as my original mechanic. Their own software apparently killed 3 brand new OEM BCM's. So they actually had to get one pre-programmed from Detroit and send it out.

Is this something I actually have to worry about? If so, and I buy a new one online, and they screw it up, how can I possibly prove it? It's got me a little worried.

Thanks

[fdryer]

With Saturn a discontinued line and dealers always looking at their bottom line, they're more inclined to control 'costs' (profits) by insisting on using their own blank bcm's if they have any. RETAIL or the equivalent of charging as much as traffic can bear. A dealer having bcm's may be more reasonable about prices if you call around. There's also the possibility of supplying a new blank bcm for a dealer to program. My guess is they're not likely to offer any warranty since its not from their inventory. It would be preferable if a Gm dealer has one or two former Saturn techs employed and familiar with scantool programs. The doors are open to negotiation. A dealer supplied and programmed bcm would be the most costly unless a dealer is accommodating and willing to keep costs down. They're still around but are in the minority and spread around the country. Check other threads about other Vue owners dealing with this issue.

Used bcm's are basically plug n' play after a 30 minute relearn and or some a better choice. Remotes need to be programmed to the used bcm with retained mileage displayed as soon as ignition is turned on.

[Chazberry]

Originally Posted by CoJames

Local GM dealer in Denver wants $462 + $140 to program it. The online one is $238. Expensive either way, but that's a big difference.

You want to find out if that dealer is quoting you a new/improved BCM with the newer style key fobs. If so, I would jump on that - $140 is the going price for programming.

I'm going through BCM hell myself right now. I tried getting my factory unit repaired, but it was toast. I got a used unit from an online outfit - very BIG PITA removing the old one. After finally getting the 30-min. security relearn accomplished, I was able to start the car and the replacement unit cured my issues (Rear Wiper, DRLs, Door Locks), but it left me with a new Air Bag Light, non-working key fobs and of course, the mileage of the car it came out of. I believe these issues can be fixed with programming by someone with a GM Tech-II scan tool. From what I understand, the "primary key" is a setup needed so the SDM can get the vehicle configuration from the BCM. I'm having trouble getting this done - the dealers want to sell you a new and improved BCM, which, from what I hear, costs about $1,000, but comes with 2 new key fobs. I would hate to spend that much on my 13-year-old '03, but I think my VUE has a lot of miles left in it, so I might spring for the new BCM. Especially considering another 1st gen unit is going to fail again in due time.

[far2grumpy]

Chaz ... my SDM went tango uniform ... family mechanic found rebuilt SDM ... installed and took Vue to local body shop ... they used tool to put new SDM number in existing BCM which costs $75.

I'm guessing many body shops have a programming tool ... just imagine how much SIR stuff they replace ... and if they don't do in house will certainly have contact with local auto electric shop ... I doubt if any take vehicle to a dealer.

It may be wise to lift center console and capture SDM serial number ... they'll surely take your word for it.

[Chazberry]

Originally Posted by far2grumpy

Chaz ... my SDM went tango uniform ... family mechanic found rebuilt SDM ... installed and took Vue to local body shop ... they used tool to put new SDM number in existing BCM which costs $75.

I'm guessing many body shops have a programming tool ... just imagine how much SIR stuff they replace ... and if they don't do in house will certainly have contact with local auto electric shop ... I doubt if any take vehicle to a dealer.

It may be wise to lift center console and capture SDM serial number ... they'll surely take your word for it.

Thx f2g - I'm gonna try this as soon as I get my VUE running again - waiting for another ECM.

[far2grumpy]

Originally Posted by Chazberry

Thx f2g - I'm gonna try this as soon as I get my VUE running again - waiting for another ECM.

I've not been keeping up with your posts because I'm typically of zero worthwhile assistance with the mysterious 3.0.

You are one sharp Vue mangler but are you certain you don't have flaky main relay?

There seems to be a rash of intermittent control wires between ECM and Main Relay lately - mostly 2.2 but I recall one or two 3.0.

[Chazberry]

Originally Posted by far2grumpy

You are one sharp Vue mangler but are you certain you don't have flaky main relay?

Not really. My L81 was stalling more and more - random misfires until it would barely idle. A used ECM got it running great again, but only for a couple weeks when it stalled and wouldn't restart. If another ECM doesn't do the trick I will definitely look into that Relay. Thx for the tip.

[CoJames]

Thanks for the info. I will try calling around to see if any of the local GM dealers might negotiate on price - the one I contacted did not have it in stock.

The used BCM sounds good, but I was under the impression that more settings needed to be programmed than just the remotes. So you're saying I could get any L-series BCM, and as long as I don't care about the door remotes or the mileage it should just drop in and work? I can live without the locks, and I already have over 250k, so I don't really care about the mileage.

That sounds like my best option, if I understand you correctly.

[Chazberry]

Originally Posted by CoJames

The used BCM sounds good, but I was under the impression that more settings needed to be programmed than just the remotes.

That's right. As I stated in my earlier post, the "primary key" is a setup needed so the SDM (Sensor and Diagnostic Monitor) can get the vehicle configuration from the BCM (That's the $140 programming). I suspect that is why I have an Air Bag Light with this used BCM. If you wind up with the same issue, you may not be able to pass a State inspection.

[CoJames]

Great, thanks. As luck would have it, I was in a wreck with the Saturn yesterday so it may all be a moo point now... we shall see.