Z4 top down light blinking
- Thread starter Idrisz4
- Start date
Hi & Welcome.
Your problem is that your lower Hall Sensor has probably become dislodged so the roof isn't seeing the signal to say its fully down and able to tell the roof motor to stop (Does the motor keep running until you take your finger off, rather than stop by itself ?)
Its a simple fix and the sensor can even be glued back into position if the little fixing tab has broken off. However, you will need to lift the left hand side of the roof out to access the sensor as its below the passenger side hinge.
Where abouts in the UK are you as there are a couple of forum members that can do this cheaply for you rather than going to a main dealer ?
This is the roof up sensor. (The 1cm square cube) The Down sensor is a little way below it on the outside.
Your problem is that your lower Hall Sensor has probably become dislodged so the roof isn't seeing the signal to say its fully down and able to tell the roof motor to stop (Does the motor keep running until you take your finger off, rather than stop by itself ?)
Its a simple fix and the sensor can even be glued back into position if the little fixing tab has broken off. However, you will need to lift the left hand side of the roof out to access the sensor as its below the passenger side hinge.
Where abouts in the UK are you as there are a couple of forum members that can do this cheaply for you rather than going to a main dealer ?
This is the roof up sensor. (The 1cm square cube) The Down sensor is a little way below it on the outside.
Hi there,
Thank you so much for your reply. Yes, you’re right the motor does indeed keeps running even though the top is down until I release my finger off the button.
Actually I live in the US, California. Therefore I guess I will give it a try fixing this problem on my own. However, is the sensor always sits below the passenger hinge? Because Passengers over here sits over the right side of the car so is the sensor sitting on the right as well?
Thank you,
Thank you so much for your reply. Yes, you’re right the motor does indeed keeps running even though the top is down until I release my finger off the button.
Actually I live in the US, California. Therefore I guess I will give it a try fixing this problem on my own. However, is the sensor always sits below the passenger hinge? Because Passengers over here sits over the right side of the car so is the sensor sitting on the right as well?
Thank you,
Hi
I believe it’s the same even on a LHD car. With the roof down, look for the upper sensor on your drivers side and if you can see that, then it will be about 3cm below it.
In the photo, you can also see the top sensor but the lower Sensor should be fixed to where I’m pointing but it’s broken away from the tab which is still screwed down, yet the sensor is dangling free
I believe it’s the same even on a LHD car. With the roof down, look for the upper sensor on your drivers side and if you can see that, then it will be about 3cm below it.
In the photo, you can also see the top sensor but the lower Sensor should be fixed to where I’m pointing but it’s broken away from the tab which is still screwed down, yet the sensor is dangling free
Hi there,
Yes you’re right he did. But yesterday when I was looking for the lower sensor I couldn’t lift the left side roof. I found 2 big bolts on the left side roof that was attached to the soft top right behind the upper sensor. I wanted to remove those bolts thinking I might get access to the lower sensor but I didn’t want to risk it. That’s why I came back asking for more instructions
I’m clearly a newbie huh lol
Yes you’re right he did. But yesterday when I was looking for the lower sensor I couldn’t lift the left side roof. I found 2 big bolts on the left side roof that was attached to the soft top right behind the upper sensor. I wanted to remove those bolts thinking I might get access to the lower sensor but I didn’t want to risk it. That’s why I came back asking for more instructions
I’m clearly a newbie huh lolI'm afraid you'll have to remove the parcel shelf, undo all the left hand side hoop bolts, and then remove all of the stuff holding the hinge in position by your drivers door. Thats the vent, grommets door rubber, electrical connections, 2 hex bolts, and the rear roof seal rubber, before lifting the roof out. - Quite a job if you dont know what your doing or have the correct tools . (45 mins if you do though).
I've never tried it, but if you've some sort of remote gooseneck camera thing you may be able to worm your way in and see what your doing without taking everything out.
Have you confirmed the sensor is hanging loose before you go to all of that trouble?
I've never tried it, but if you've some sort of remote gooseneck camera thing you may be able to worm your way in and see what your doing without taking everything out.
Have you confirmed the sensor is hanging loose before you go to all of that trouble?
Hi
Yes indeed that sounds much of a work. While surface inspecting I actually cannot confirm if the lower sensor is hanging loose. I tried to trace the lower sensor wire since it was exactly routed like the picture you provided. The lower sensor wire is routed between the upper sensor then goes down and after it is tucked beneath the upper sensor in which I was unable to trace after because no access. But when I place my flash light on that area I can see what look like the lower sensor placed beneath the upper sensor and I tried to stroke it to see if it was loose but it seems it was sitting firm. But yet, I still am not sure if that the lower sensor.
Yes indeed that sounds much of a work. While surface inspecting I actually cannot confirm if the lower sensor is hanging loose. I tried to trace the lower sensor wire since it was exactly routed like the picture you provided. The lower sensor wire is routed between the upper sensor then goes down and after it is tucked beneath the upper sensor in which I was unable to trace after because no access. But when I place my flash light on that area I can see what look like the lower sensor placed beneath the upper sensor and I tried to stroke it to see if it was loose but it seems it was sitting firm. But yet, I still am not sure if that the lower sensor.
Hi,
You’re right! I raised the top a quarter and I was able to clearly detect the lower sensor. However, the lower sensor was not dislodged. It was sitting vertically underneath the upper sensor. I tried to poke it to see if it would shake but no it was sitting firm. It seems the lower sensor is not the problem right?
You’re right! I raised the top a quarter and I was able to clearly detect the lower sensor. However, the lower sensor was not dislodged. It was sitting vertically underneath the upper sensor. I tried to poke it to see if it would shake but no it was sitting firm. It seems the lower sensor is not the problem right?
Well, its eliminated it being dislodged, but suggests its either just not working or there is an issue with the detector loom between the sensor and the Roof ECU.
Your getting into technical territory now, beyond a simple DIY fix, so you may need to seek more expert help locally now I'm afraid.
Its a case of taking off the inner roof liniing, the access panel to the claw motors and threading a new loom all the way through and down to the roof ECU. I've done a couple but its a pig of a job, and you'll need a new or second hand loom too.
Sorry to be the bearer of bad news. Otherwise just live with the flashing light ?
Your getting into technical territory now, beyond a simple DIY fix, so you may need to seek more expert help locally now I'm afraid.
Its a case of taking off the inner roof liniing, the access panel to the claw motors and threading a new loom all the way through and down to the roof ECU. I've done a couple but its a pig of a job, and you'll need a new or second hand loom too.
Sorry to be the bearer of bad news. Otherwise just live with the flashing light ?
Oh i see, I definitely can live with the flashing light in that case lol but really thank you man for all the info and suggestions. I truly appreciate your help 
I had had another question for you though. So since my Z4 is a soft top, I have been researching about soft top issues and it seems rain can cause soft top motors go bad since it will be socked with water due to clogged drain. I was wondering if there is a solution to that problem other than relocating the motor?
I had had another question for you though. So since my Z4 is a soft top, I have been researching about soft top issues and it seems rain can cause soft top motors go bad since it will be socked with water due to clogged drain. I was wondering if there is a solution to that problem other than relocating the motor?
