Security light pops on intermittently

[Randy Whistler]

OK, this is one of those things that happened that made me think I was crazy, but I saw it happen a couple of times, so I'm not totally nuts - well about this, anyway. . . .

Sometimes, when driving or setting still running, the security light will come on for a few seconds, then go off. Other than popping up from time to time, it doesn't seem to cause any problem other than making me feel crazy. Further investigation showed me that the light seems to come on when the vehicle is experiencing a heavy voltage load - idling with the A/C running at a drive-thru, waiting at a stoplight with everything running, etc.

My guess, based on the above, is that the truck is pulling too much voltage load that triggers the light to come on then go off. I've not done any extensive testing, nor been smart enough to glance at the voltmeter to see if the voltage dropped, but that seems to be the most logical thing I can figure out at this time.

Is this unique to me, or a more common problem? I've read several threads that mention a security light problem but most of them to seem to be related to the light staying on until the vehicle is shut off, rather than on and off in a couple of seconds.

 

[SnowDrifter]

What year? Pass lock can be a bit finicky. It was discontinued in later trucks

 

[Randy Whistler]

What year? Pass lock can be a bit finicky. It was discontinued in later trucks

2000 LS

 

[Randy Whistler]

Jiggling the post. . . what is Pass Lock? could it be a BCM issue as I've read elsewhere? It happens regardless of which key is in the lock, so I feel OK it's not keys, but wondering about the lock cylinder being dirty, etc. .

Open to any and all suggestions.

 

[royesses]

My 2002 GMC Yukon Denali did that for a couple of years. I finally got sick of it and replaced the passlock control in the steering column. It requires some tooling, I made some of the tools and it requires a steering wheel puller. Then it must be programmed into the ecm. This can be done without a scanner but takes 20 minutes.

Roy

 

[JonnyTahoe]

Mine just started doing that but stays on till I turn the ignition off then seems to go back to normal.

 

[Randy Whistler]

OK, now, I cannot say this fixed this security light issue, but the light hasn't come on since, so. . . . . .

I found I could replicate it by loading up the system, like running the A/C and front and rear fans. When I started having the sputtering issue(posted elsewhere), I started checking electrical connections. I found a braid, at the rear of the engine, that was supposed to connect to the firewall. The braid was split in half. I repaired the defective wiring and that appears to have fixed the security light issue. It did nothing for the sputtering(fuel pump), but does appear to have fixed the security light problem.

Hope this helps someone along the way. . I just love weird, intermittent stuff. . . .

 

[ivin74]

Glad to hear that was a simple fix, I have read tons of threads like this one and lots of times it's a worn out a ground cable.