Alarm malfunction

[bkgee]

Folks, I figured I would document my new alarm system malfunction here now. I searched everything I could find for alarm problems, and there only seem to be a couple with similar symptoms as mine, and no obvious solution. I will be taking the truck to the dealership today, hopefully they can diagnose for me, and I will even let them fix it if they are reasonable.

Symptoms = alarm activates without any apparent trigger, horn beeps (beep-beep-beep style, not continuous) and lights flash. Alarm stops when engine is started. Shortly after stopping the engine, alarm sounds again. This is a 2001 LC.

This problem started yesterday around 7:30 AM, and my neighbor disconnected the battery (I was already gone to work). Yesterday afternoon, I reconnected the battery, and there was no alarm at first. Some time later, the alarm kicked in again. I disconnected the two horns mounted in front of the radiator (I left the round buzzer style horn connected, mounted on passenger side of engine compartment), and did not have any problems for the rest of the night. This morning, the alarm began sounding again before I left for work around 7:30 AM again. I disconnected the round buzzer style horn, and brought the cruiser to work with me. The horn relay (?) began clicking and the lights began flashing within a couple minutes of shutting the engine off.

We have had no rain or freezing temperatures at all lately. I have no idea what the problem is, and have no electrical skills anyhow. If anyone has any solid info, or even some good guesses, please post! I will follow up here when I learn more...

 

[bkgee]

OK folks, I am picking my truck up from the shop this evening, ended up going to a brick n mortar yoda shop here that i've been using for 15 years instead of the dealership (The Auto Clinic, used to the Toyauto Clinic until Toyota lawyers called them a few years ago).

I spoke to the technician that worked on the truck for 1/2 hour which included a brief electrical diagnostic, and then he performed a "reset the alarm". I inquired what was entailed in resetting the alarm. He said the procedure is to first turn the ignition to the ON position (yes, past ACC), then connect the battery (the alarm might begin to sounds after some delay, as i described in the first post above), then you cancel the alarm with the key fob (open doors button), then you can remove the key or turn her over. This tech (Wyatt) has been at the Clinic for several years, and was at the local dealership for a few years before that, and said he gained his knowledge of the alarm system there.

He elaborated that the alarm on these trucks is very sensitive to electrical voltage changes (and is very complex over all), and that my alarm could have been tripped by several things which may have caused a small change (eg, poor battery terminal connection, I need to do a little work on my batt config). Or I could have had a prowler. But as described above, the battery was disconnected/reconnected several times, but the alarm was never "reset" properly. Each time I reconnected the batt, the alarm system woke up and remembered that it was triggered before the power was pulled.

Does anyone have any experience to support or refute any/all of this? I will post again if the problem crops back up.

 

[JEMJR]

My 98 has been doing the exact same thing. Mechanics thought it was the driver side door switch, so I had that repaired and it still did not fix it. Have you had any luck determining the cause of the problem?

 

[bkgee]

the problem i had was fixed as described above. its been several days now without a recurrence.

 

[thibaut]

Very interesting. I have the same issue with alarm going off without apparent cause. Various garages including toyota dealers and specialised independent have offerred different explainations ranging from sensors becoming too sensitive with age or very hard to get problem buried deep inside car electrics. None was able to cure it and since i am happy to just use the locks i didnt bother further. I should give this a try.
Best
T

 

[bkgee]

^please post back with your results

 

[uHu]

One problem experienced by a few in our local LCclub is:
Loose connection and/or moisture in a plug in the upper tailgate. It's for the tailgate lock switch, and situated in the lower left corner. The plug housing is wrapped in foam, so that if it gets wet, it stays wet. Great.

I once had symptoms similar to yours, and I just checked this plug (it was dry), put on some contact cleaner, and problem was gone.


Removal of upper tailgate trim:
1
On the doorhandle, remove the two tiny covers for the crews. Remove the screws with a pz-2 driver. Pull of the cover around the handle.
2
The upper plastic panel has to be loosened along the bottom for removal of the lower panel. It is fastened with plastic clips which are reusable with some luck and care. Pull the clips at the sides sideways, i.e. pull the left wing towards the right and v.v. Use a flat blade screwdriver with some tape wrapped around it and a "door panel removal tool" (I found a cheap one that fits perfectly). If you want to remove the whole panel, then the upper clips are pulled out perpendicular to the door.
3
The lower panel pulls straight out (perpendicular). Use the door panel tool.

 

[Phrog]

A weak battery can put out slightly lower voltage that normal, and some
electrical systems in the car can get confused by that. It's a long shot - but
check your battery. My Volvo alarm went off without any apparent
trigger, and after much head-scratching I figured out it was a dying
battery.

-Phrog

2003 100

 

[bkgee]

thanks for that. my batt is almost new, i think it was poor connections for me

 

[stinkyfj60]

i am bumping this so that i can find it later...

my Hundy did this to me a few weeks ago, but there were high winds and I just figured that a big gust hit it and set it off...

last night, at 11:30 it went off and it was a completely calm night. who knows, i will look at some of these trouble shooting things.