XJ XJ6 / XJR6 ( X300 ) 1995-1997

alarm system hard reset

Old 02-17-2019, 09:53 PM
Junior Member
Thread Starter
Join Date: Sep 2013
Location: Port Towsend WA
Posts: 26
Received 5 Likes on 4 Posts
Default alarm system hard reset

Hello to all, I am working on a friends 1996 VDP ( I have lots of X300's of my own as well,not to mention a 72 XJ6 with 475,000 miles ) so anyway the 96 I was doing some work in the drivers door, you know the usual, broken door check, stretched door latch cable, and installing a missing link from the key lock barrel to the lock latch. Anyway while doing this I unhooked the electrical connector to the latch and that tripped the alarm. So had to disconnect the battery, but after reconnecting the wires and hooking up the battery the alarm is still engaged. So I obviously need to reset the alarm, so the question is how do you do that. There is no key fob for the car just keys, ( which is why I had to hook up the door key barrel to latch switch ) so I have searched and searched and found references to a hard reset, but I cannot find how this is done,
Please a little help
Old 02-18-2019, 04:44 AM
Steve M's Avatar
Veteran Member
Join Date: Jul 2012
Location: Wiltshire, UK
Posts: 3,823
Received 1,226 Likes on 927 Posts

I think that a hard reset is not just limited to any one system.
I believe that it just involves disconnecting the positive battery clamp and attaching it to the negative clamp (not the other way round) for a few minutes.
Kind of like ctrl-alt-delete for your computer.
I think it just realigns the chakras or something.
Check before you do it in case I am completely wrong!
Old 02-18-2019, 09:42 PM
Lady Penelope's Avatar
Veteran Member
Join Date: Apr 2017
Location: Kansas City USA
Posts: 3,774
Received 1,213 Likes on 965 Posts

For US cars without the security feature in the original stereo

My recommendation is to remove both cables and bring both together in the air

This reduces the notion of which one cable to remove

Sometimes the cables touching takes some time so by placing a towel or cardboard box over the terminal posts and using your jumper cables to connects the 2 battery terminal wires together can be left overnight

I have found the longer time clears up the stubborn hangups

This reset will effect the engine ECU so on startup you may notice the engine perform better until the engine relearns the perimeters for pollution control which degrades the engine performance

Last edited by Lady Penelope; 02-18-2019 at 09:54 PM.
Old 02-20-2019, 02:30 AM
SleekJag12's Avatar
Veteran Member
Join Date: Dec 2012
Location: Scottsdale, Arizona, USA
Posts: 1,096
Received 318 Likes on 248 Posts

Seems like you would know this already, but anyhow:

Disconnecting the battery does not pull the car out of alarm mode, as you found out. The key fob does not clear alarm mode either. To reset it, you need to put the key into the ignition and turn it on. That's the only way to reset an alarm activation.

I don't think even the "hard reset" will clear it, but let us know what you find out.
The following users liked this post:
Don B (05-25-2019)
Old 02-20-2019, 02:44 AM
GGG's Avatar
GGG is online now
Join Date: Dec 2011
Location: Durham, UK
Posts: 108,833
Received 10,233 Likes on 8,414 Posts


If simply disconnecting the battery or even doing a "hard reset" disarmed the alarm system, it might as well not be fitted! The system is designed to do precisely what you found. The alarm will go off again when the battery is reconnected:

As suggested, put the key in the ignition and turn it to deactivate the alarm.

The following 2 users liked this post by GGG:
Don B (05-25-2019), Lady Penelope (02-20-2019)
Old 02-21-2019, 11:49 AM
Junior Member
Thread Starter
Join Date: Sep 2013
Location: Port Towsend WA
Posts: 26
Received 5 Likes on 4 Posts
Thumbs up problem fixed

Thank you everybody for the help,
As you have noted, doing anything regarding the battery had no effect, both touching the leads together for any time period, to touching the neg lead to the pos lead while the pos lead was still attached to the battery, ( with the key on ) also had no impact.
Also I should note, that the car would not start, nor disengage the alarm ( I know it is a NA car, without immobilizer, but it would not turn over ) the only thing that worked was key in the driver door, locking and then unlocking, did the trick.

Anyway thank everyone for the help.
Got her back on the road and now she can lock her car, so she is happy


The following users liked this post:
Lady Penelope (02-21-2019)
Related Topics
Thread Starter
Last Post
XJS ( X27 )
04-11-2019 10:55 PM
XJ XJ6 / XJR6 ( X300 )
10-20-2014 07:20 PM
S-Type / S type R Supercharged V8 ( X200 )
04-27-2013 10:40 PM
jag 3
General Tech Help
07-31-2012 04:44 AM
S-Type / S type R Supercharged V8 ( X200 )
05-04-2007 05:51 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Thread Tools
Search this Thread
Quick Reply: alarm system hard reset

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
  • Ask a Question
    Get answers from community experts
Question Title:
Your question will be posted in: