Car Alarms: Disable an alarm, keyless entry system, negative pulse


Question
How can I deactivate the alarm on a 2000 Toyota Sienna van?

The problem.........
I check on the house of friends who are visiting family in Va. and should have been back a month ago, but their visit has been extended because of a serious illness of a sister.  I tried to take their van for a spin but the battery is totally dead  

He said it was 3 or 4 yrs. old and ask me to replace it.  As soon as the new battery is connected, the alarm kicks in with the horn, lights, locking the doors and disabling the starter.  I have tried many remedies from friends and online, and could not find any valet/override button or toggle switch.  I found out the alarm will stop when I hold down the "lock" button on the keyless remote but the "unlock" button has been disabled.  So I can unlock the door with the key but as soon as I open door, the alarm kicks in again.

The van came with the alarm system but he doesn't know if it was factory or dealership installed.

They are good people who always help anyone in need and have been through a lot so I really would like to have their van ready to go when they return.

Thank you, Ken Stokes
.

Answer
Ok, a bit complicated.
 This system depends on the physical action
of the door lock locking and unlocking-arming and disarming.
If you have a factory remote, that would do this to
specifications.

This can only be achieved 3 ways:

1. Use key in the drivers door, turn left,
then right to disarm and unlock.

2. Add an after market keyless entry system to emulate
the factory remote functions. I have several models
if this option suits you.

3. Acquire or use & or, replace the original remote that
can control it as specified. This would be at the
local dealership parts department.

(This is why there is no wire you could ground
without affecting the door lock system.
A single negative pulse to the unlock wire will disarm
without unlocking, yes, but would always disable the
locking mechanism. Not good.)

Keep in mind, if this is after market
(siren and flashing parking lights)
then it's a different method entirely.

The standard method to disables as follows:

Look under the dash area for a button or, a toggle
switch. When you locate it, turn on the ignition
key, press and hold in the button (little
spring loaded micro button, red or black possibly)
until the alarm chirps 1 time. This should over ride
the system, and only the keyless entry part,
if installed, would still be operating.
The LED (light emitting diode) light in the dash
should also go on solid. If it's a toggle type,
then key on, flip the switch in the other direction
This would be OVERRIDE/VALET mode.

Repeat this process to toggle back to service mode.

Lastly this car has a transponder in the ignition key
and ignition column. if this system is in "TAMPER MODE"
and the fuel rail has shut down, there is nothing
you can do personally to disable it. The dealer will need
to put it into a diagnostic reset through they're
code reader writer system in the service dept.


Let me know what applies
to your issues.

R. Martin - ALARMTEK