Hello fellow Saturn owners. Wondering if others have had issues with BCM failures? Own a 2008 Vue XR AWD, 3.6L. Have been experiencing intermittent power loss to radio and instrument cluster. I thought perhaps corroded neg battery terminal, so cleaned. Seemed to correct problem for a month. In addition to power loss in dash, charging system is intermittent. Alternator bench tests fine. Battery load tested okay. No obvious wire breakages in charging system. Door locks will occasionally/often not function properly, and recently rear hatch will not unlatch with button. Has anyone else had similar issue and BCM was the source of problems?

 

90% are replaced while having no problems.
Check the grounds.

https://charm.li/Saturn%20Truck/2008...rounds%20List/

Look at the diagrams.
Radio:
https://charm.li/Saturn%20Truck/2008...em%20Diagrams/
IP:
https://charm.li/Saturn%20Truck/2008...er%20Diagrams/

 

Check for corrosion under the battery cable insulation. If you see green, you've got it. Have you had the battery load tested? I'm in agreement with Gary that most BCM replacement doesn't solve the issue.

 

+1, sounds like a grounding issue or intermittent connection from the battery to the under the hood fuse box

I owned the exact same vehicle for quite a few years.
I don't remember for sure, but I think it ended up being an intermittent connection/poor connection at the positive battery terminal where it connected to the cable. I believe there was corrosion and/or battery acid leakage that could not be seen without undoing the positive cable connection.
Same test results. Entire charging system usually seemed fine, but the way that positive harness attaches to the alternator and the starter. I believe made it possible that the alternator output could go either to the battery or directly to the underhood fuse box.

So it was possible that the vehicle would sometimes charge the battery properly and supply the vehicle with operating current, but it was also possible that the alternator output would not get to the battery and the car would be running off of the battery instead of the alternator, very intermittently.

Reviewing the above, I believe it makes absolutely no sense and is probably incorrect. I won't erase it just in case it prompts anything in your mind to check.

Maybe the corrosion was at the starter. It's one of those harnesses where unexpected current pants can arise depending on what is not working properly. I honestly don't remember any more than that.

I suggest, ultimately, also checking the positive connections everywhere on that harness. For example, if you get a low enough voltage and current going to the PCM and through the fuse box, something simply won't operate due to a lack of current at the correct voltage. Look at the harness and draw what it connects to out on paper and you'll see what I'm talking about. It's the intermittent connection that affects both the battery charging and the current to the fuse box.

If the above is completely off, I do apologize. I have memory issues. But I would still check those positive connections.