Disable the stock (?) alarm so I can safely reconnect the battery - Toyota Yaris Forums

frankienap · 01-18-2016, 02:02 PM

Hello all,
I have a 2008 Yaris Sedan. I'm the second owner and I believe the car has the stock (OEM) alarm system (not an aftermarket) installed. In the past when I've needed to unplug the battery to work on the car, I've also been hesitant because when reconnecting the battery the car alarm sounds immediately, which is pretty scary when you're working on a car and holding a battery terminal.
I'm looking to do some work on my car this weekend and what an answer to this question once and for all: how do you disable the stock alarm so that you can safely unplug and reattach your battery without the alarm going off?

I've searched the forums, but without luck. I even downloaded the "2008 Toyota Yaris - Theft deterrent system" manual from Toyota. Very confusing stuff. To deactivate the alarm, it says:

Unlock the doors or trunk using the key (vehicles without wireless
remote control) or wireless remote control door lock function
(vehicles with wireless remote control).
l Start the engine. (The alarm will be deactivated or stopped
after a few seconds.)

Then it later says

When the battery is disconnected
Be sure to deactivate the alarm system

Okay. But how do I deactivate the alarm when the battery is disconnected? The key FOB obviously doesn't work when the battery is disconnected.

Confused and looking for help.

jcboy · 01-18-2016, 05:08 PM

it probably means when the battery is disconnect and then reconnected, then be sure to deactivate the alarm using the key fob.

just my 2 cents.

CTScott · 01-18-2016, 07:31 PM

The OEM theft deterrent ECU is powered by the DOME, ECU-IG and ECU-B fuses. Pulling the DOME and ECU-B fuses would keep it from firing as soon as you connect the battery.

frankienap · 01-19-2016, 11:59 AM

CTScott,
Thanks. I'm going to try that later tonight. I'll confirm if that disables the alarm.

01-18-2016, 02:02 PM	#1
frankienap Drives: Yaris 2008 Sedan Join Date: Apr 2012 Location: Cambridge, MA Posts: 10	Disable the stock (?) alarm so I can safely reconnect the battery Hello all, I have a 2008 Yaris Sedan. I'm the second owner and I believe the car has the stock (OEM) alarm system (not an aftermarket) installed. In the past when I've needed to unplug the battery to work on the car, I've also been hesitant because when reconnecting the battery the car alarm sounds immediately, which is pretty scary when you're working on a car and holding a battery terminal. I'm looking to do some work on my car this weekend and what an answer to this question once and for all: how do you disable the stock alarm so that you can safely unplug and reattach your battery without the alarm going off? I've searched the forums, but without luck. I even downloaded the "2008 Toyota Yaris - Theft deterrent system" manual from Toyota. Very confusing stuff. To deactivate the alarm, it says: Unlock the doors or trunk using the key (vehicles without wireless remote control) or wireless remote control door lock function (vehicles with wireless remote control). l Start the engine. (The alarm will be deactivated or stopped after a few seconds.) Then it later says When the battery is disconnected Be sure to deactivate the alarm system Okay. But how do I deactivate the alarm when the battery is disconnected? The key FOB obviously doesn't work when the battery is disconnected. Confused and looking for help.

01-18-2016, 07:31 PM	#3
CTScott ULTIMATE View User's Garage Drives: 09 5dr LB, 2x 08 3dr LB Join Date: Oct 2008 Location: USA, CT Posts: 13,460	The OEM theft deterrent ECU is powered by the DOME, ECU-IG and ECU-B fuses. Pulling the DOME and ECU-B fuses would keep it from firing as soon as you connect the battery. __________________

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01-18-2016, 05:08 PM	#2
jcboy Drives: Sedan 07 Join Date: Oct 2012 Location: Asia Posts: 478	it probably means when the battery is disconnect and then reconnected, then be sure to deactivate the alarm using the key fob. just my 2 cents.

01-19-2016, 11:59 AM	#4
frankienap Drives: Yaris 2008 Sedan Join Date: Apr 2012 Location: Cambridge, MA Posts: 10	CTScott, Thanks. I'm going to try that later tonight. I'll confirm if that disables the alarm.