security light

hey guys,
2000 4.8 2WD, AC and nothing else. sometimes my security light comes up while driving. any ideas????
i worked for a guy some time ago, he had a pickup similar to mine, and once the security light came on upon inserting keys to the ignition, you couldnt start the truck for a while, sometimes an hour to three, but after it would start right up like nothing happened.
Also my truck has no power locks, power windows, etc....

maybe linked to your doors being somewhat ajar? (maybe the door jamb switch?)
thats a weird issue. Maybe reset the PCM by unplugging negative battery terminal for 30 minutes - 1 hour? Kind of like a reboot.

Good luck

This is a little off the subject but, after disconnecting neg side of battery for half an hour or so, dont you have to let the truck run for a certain amount of time before driving?
Thanks,
Joe

No you do not have to let the truck idle/run before driving.........

You only loose some short term memory that the PCM uses to set LT/ST trims among a few other items.

Check if your radio has Theftlock beforehand. There's a way to deactivate it (if you have the code) so that you can unhook the battery. If not, there's a sticky thread about unlocking.

Check if your radio has Theftlock beforehand. There's a way to deactivate it (if you have the code) so that you can unhook the battery. If not, there's a sticky thread about unlocking.
What happens if I do but I dont deactivate it beforehand? I already did the "reboot" deal before getting your reply.

Joe

Is your radio locked then? There's a sticky thread on top of the forum with unlock instructions. I've never had to do it, but the posting makes it seem pretty easy.

Okay, guess I lucked out. Just checked my radio & it's not locked. Dont know why. BTW, it's an '05 Z71 ext cab.
Joe

Well, that's good! Maybe the newer ones are different - not sure. My '02 specifically mentions it in the owner's manual somewhere. Did the reboot fix the security light problem?

Purple_haze was the one with the security light problem. I was just wanting to try the "reboot" because I recently installed one of Fram's new cold air intake systems. I thought maybe it was a good time to "reboot". Don't know if it'll change anything.
Later.
Joe