Tutorial: Remove Is200 Roof Lining And Fix Alarm Problem

[Mshipman]

So for the last few month I have been having problems with my 99' Lexus IS200. It seems that there was a problem with the alarm that has been setting is off at all hours of the morning. The only way I found around it was to leave my car unlocked over night, which wasn't very comforting. So I was reading around the forums for a fix but I couldn't find a clear solution for it. I found that it may be the motion sensor that was causing the problem but I couldn't find out if it could be disabled or how to disable it, so I went hunting.

I decided that I would remove the roof lining and heat shrink all the wires as this may have been the problem. After pulling my entire roof apart I found that the motion sensor itself was inside the dome light and that it was as simple as unscrewing 3 screws and disconnecting a single harness. So if you are having the same problem try disconnecting it before you go ahead and waste a lot of time haha. I have only just disconnected the sensor so I'm not 100% sure if it is the problem but I'm certain that it is. I will post back in a few days telling you how I go.

Disable motion sensor

Time: 5 minutes

Difficulty: Easy

Motion sensor harness:

The big circle is the motion sensor.

The small circle is the harness to disconnect.

Removing roof lining

Time: 40 minutes

Difficulty: Intermediate

1. Remove the A-pillar by gently pulling.

2. Remove the B-pillar by removing the seat belt cover, unbolt the 14mm seat belt bolt and gently pull the cover off.

3. Remove the C-pillar the same as the A-pillar.

4. Remove the map light by pulling down or prying it.

5. Remove dome light by removing the lens cover and unscrewing the 3 screws.

6. Remove rear-view mirror by prying the cover and removing the 2 screws.

7. Remove the sun visors by removing the 2 screws on the outer side, disconnect the harness and remove the screw holding the pivot point.

8. Remove the grab handles by removing the covers on the end of the handles and unbolt the 2 bolts on either end.

9. Remove the 2 push in clips near the rear window(sorry no pictures)

10. Remove the roof lining. The roof lining should now be completely free. The easiest way I found to get it out is by folding down the passengers seat and removing the liner through the rear passengers door.

I hope this helps anyone who is having the same problem as me. If you have an questions feel free to post of pm me.

If anyone is curious I may weigh some of the part for those wondering about weight stripping

If you would like to see more photos click the link below:

http://s839.photobucket.com/user/Matt_Shipman/library/Lexus%20IS200%20roof%20lining%20and%20alarm%20problem

[IHgs300]

Excellent guide, well done. I have pinned this for other members use.

[eigenvalue]

A nice tutorial!

Can you say if disconnecting the motion sensor did in fact cure the issue of the alarm going off in your case?

Thanks for the useful information.

[eigenvalue]

Unfortunately, in my case at least, this solution did not cure the problem.

Thanks all the same for the potentially very useful information.

[Ncc73]

As a new owner with the alarm having gone off once during the day this is a great guide on how to get to the sensor in the dome light.  If it happens again I will be getting my credit card out and disconnecting the motion sensor. 

Thanks for the photos this is a great help

N.

[gdh300]

Great guide, nice one Matt. I've had my alarm go off a couple of time at work (I bet the neighbours love that at 6.30am!) but it seems really irregular. I thought may be it was just the age of the unit, but I'm starting to think actually it might be being triggered by my tired old inertia reel seatbelts taking in the last few inches. I'm now consciously making sure they have fully retracted before I lock-up - touch wood!