Security Light Gone Haywire
#1
11-10-2009, 11:11 AM
Security Light Gone Haywire
I'm not sure if this should be posted here or in General Tech...
I've got an intermittent problem that only happens when it's cold out (like mid-40s or colder). Happened all last winter and it's happened a few mornings this fall, when the temp dropped that low.
Here's the scoop: When it's cold in the morning, I'll walk up to my car and before I even open a door or anything, I see the security light flashing like mad (about 5 times per second, but not a regular pace). Opening the door (or turning on interior lights with the door shut) makes it go even more wild. Every time the security light flashes on or off, there's a click coming from one of the relays on the electrical board of my Body Control Module (BCM) under the passenger side dash.
When this is happening, the car won't start unless I time the key-turning just right to go between clicks. It's as though the car can't figure out whether to arm or disarm the factory security system.
If interior lights are on, they flash on/off with the security light and the clicks in the BCM as well. Sometimes, this affects the radio as well.
Also, sometimes while I'm driving, the security light will come on for a few seconds and then go off. This doesn't have any other effect while driving, but happens whether it's hot or cold out.
All the info I've found about security light problems says that the first thing to go bad in that system is always the wires in the ignition lock, and that I should replace that. However, this problem occurs whether the key is in the ignition or not, so I don't think that's the problem.
Do I need to replace my BCM, or is there something else (such as low voltage from the battery) that might cause something like this to happen?
I've got an intermittent problem that only happens when it's cold out (like mid-40s or colder). Happened all last winter and it's happened a few mornings this fall, when the temp dropped that low.
Here's the scoop: When it's cold in the morning, I'll walk up to my car and before I even open a door or anything, I see the security light flashing like mad (about 5 times per second, but not a regular pace). Opening the door (or turning on interior lights with the door shut) makes it go even more wild. Every time the security light flashes on or off, there's a click coming from one of the relays on the electrical board of my Body Control Module (BCM) under the passenger side dash.
When this is happening, the car won't start unless I time the key-turning just right to go between clicks. It's as though the car can't figure out whether to arm or disarm the factory security system.
If interior lights are on, they flash on/off with the security light and the clicks in the BCM as well. Sometimes, this affects the radio as well.
Also, sometimes while I'm driving, the security light will come on for a few seconds and then go off. This doesn't have any other effect while driving, but happens whether it's hot or cold out.
All the info I've found about security light problems says that the first thing to go bad in that system is always the wires in the ignition lock, and that I should replace that. However, this problem occurs whether the key is in the ignition or not, so I don't think that's the problem.
Do I need to replace my BCM, or is there something else (such as low voltage from the battery) that might cause something like this to happen?
#3
11-13-2009, 07:10 AM
Just in case anyone else ever has this problem, I replaced the BCM last night and so far it seems to be working. I drove it about 20 miles without the light clicking on like it used to while driving. It was also really cold again this morning, and there was no problem when I got in my car to go to work.
I also noticed that the rear windshield defogger works for the appropriate length of time now. It used to click off way before I thought it ought to, and if I tried right away to turn it back on it would immediately click off. No problem with that this morning.
I'll keep posting if anything goes wrong again.
I also noticed that the rear windshield defogger works for the appropriate length of time now. It used to click off way before I thought it ought to, and if I tried right away to turn it back on it would immediately click off. No problem with that this morning.
I'll keep posting if anything goes wrong again.
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