This is a 2002 oldmobille silhouette that we have had since it had 9 miles on it. it now has 98,000.

I havent checked the resistance of my keys but this problem I am about to explain happens when either of our keys is in the ignition. All the gauges will drop to zero. The light for what gear we are in (P R N D etc) will disappear and the display will show SECURITY along with LOW FUEL even though I have a full tank of gas. This will last for a few seconds and while driving it will all go back to normal (security light will stay on). If I pull over turn it off then back on the security light disappears and everything goes back to normal (which tells me its not ignition related since if it was the van wouldnt start for 10 minutes). It is intermittent. However I have checked all the ground connections as well as battery connections and all fuses. I am down to checking the resistance of both keys in the ignition (havent done this yet) before going to the BCM but I am leaning towards BCM because...

1. the above problems
2. The passenger sliding power door randomly loses power and has to be manually opened or closed. This has been happening since we bought the van brand new and the dealer couldnt find anything other than to say "the track is dirty" which it never is.

3. there was another issue but right off the top I cant think of what it was that is happening off and on that is also controlled by the BCM.

4. the sliding door locks randomly lock and unlock as it so pleases.

any other ideas?

I forgot to add that the radio dies as well.

 

I "think" I may have found the problem. There are two sensors in front of the radiator (one on passenger side one on drivers side) one of those plugs was loose. So I pushed it back in. This van usually everything posted above would happen within 3-5 miles of driving anywhere. we drove it over 60 today and it never happened. Also I was getting misfires and now it doesnt happen at all. I didnt think the BCM would have anything to do with misfiring but it seems to have fixed the problem by pushing that plug back in. I will give it a few days to make sure.

 

I hope that works for you, post back after a while and let us know. BCM issues (other than total failure) are usually very hard to diagnose.
On a GM product, I would almost always replace the ignition switch before buying a BCM, as a bad switch can cause numerous, varied, intermittent, random symptoms, just like a BCM.

 

no actually it didnt fix the problem... It got worse. I would think if it was the ignition though that the problem would be it wouldnt restart for 10 minutes after the security light comes on and well it starts right back up. That doesnt mean I am right just thats what I am thinking. Looking at pricing its gonna cost me $300 for an ignition switch or $300 for a BCM.

I am going to change the battery in it as I didnt think about the fact it might be dieing. It is 9 years old (so yes still origional battery). Van still starts fine and is still putting out 12.5 volts when vehicle isnt running and 14 when it is running but that doesnt mean the battery can handle the extra required to run everything. So I am going to try that first. I am going to take the battery in to get tested at auto zone but I am still going to replace it as well I have gotten bout 4 years longer out of the battery than I probably should have lol. Though I do tend to get between 7-9 years out of the batteries in every vehicle I have owned except my motorcycle which is 3 years.

 

The 10 minute restart thing is only one of the many problems a bad ignition switch can cause, and is a failure of the Passlock security system sensor in the switch.
I would change the battery, but I don't think it will fix your problems. The alternator should supply around 14 volts to the system when running, so a bad battery wouldn't matter (in theory!). Let us know if a new battery helps.

 

Ok I havent changed the battery yet (working 7 days a week leaves limited time). I did have it tested at autozone while in the vehicle and under load it dropped to 10 volts.

My question is when I put the key in the ignition it starts out at 12 Ohms (meter at the brown and green wires) and then drops to 11.5 Ohms. If I move the key any which way it jumps anywhere from 5-200 ohms depending on how I move it. So would this mean just changing out the tumbler and the black box which I can only assume is the ignition switch below the tumbler?

 

ok I changed the battery today. Took 30 minutes cause I had to drive to autozone to get the new battery lol. in reality labor wise took me 15 minutes. Amazing since the book says 45 minutes ok not really but hey I saved myself half our according to book lol.

Anyways sorry to go on a tangent but The battery didnt fix it (autozones program said it was a bad battery even though under load it only dropped to 10.2 amps.).

So I checked online at autozone and the picture of the ignition switch doesnt match my wiring. The harness has a screw to hold it into place but the one on my van goes all the way down the column to A steering control box. Probably 2 and a half feet of wire. Is this normal????? oh and the switch is only $61 sweet. I am assuming I dont need the switch programmed?

*edit ok wife just called and said now the sliding door wont work at all (it has always been intermittent since we bought it and dealer always told us it was "dirty")... I will check the fuse for it but unless I am missing something doesnt that point to the BCM?

*edit again
wife got home. I pulled the door fuse and it is fine. However the radio wouldnt shut off (second time this has happened). I pulled the fuse in the main fuse box (fuse #29 that controls radio and a few other things like part of the BCM and PCM). left it out for 30 seconds and reinserted. now everything works normal again. I supposed this could have something to do with having changed the battery so now I am gonna guess it is back to the ignition switch.

 

This is very interesting. I also want to hear what you find out.

Ref

 

Ignition switch did NOT fix the problem. Got 8 miles down the road and it started happening again. sssooo now I just bought the BCM for $170 on rock auto after shipping. Hopefully this will fix the problem.

However the old Ignition the ball on the safety switch was worn out.

*edit

forgot to mention that this happens when the vehicle is in park sitting idle (sits idle while we look at new vehicles lol).

 

Well I dont have the new BCM yet but I unplugged it to order a new one (wanted to make sure I got the right BCM for my van). Anyways I plugged it back in (I did all this friday) and the van hasnt done this since. Plus the drivers side slider door locks and unlocks now like it used to (instead of staying unlocked when you hit the lock key or locked when you hit the unlock key) and the passenger side automatic slider door doesnt stop anymore. So hopefully a new BCM will keep this from happening again.