Hi, I’m hoping to get a little help with a problem that I am having with my 2012 XKR convertible roof. For a little while now I’ve found when the car hasn’t been driven for a few weeks that the roof will refuse to open. It will wind the windows down, unlatch, lift a couple of inches, then stop, followed shortly by the warning message “Roof not latched”. Usually re-charging the battery fixes this, but that no longer seems to be working.

I took the battery off the car, charged it fully overnight, refitted the battery, calibrated the parking brake, calibrated the windows, but the same behaviour remains. The windows drop, the roof unlatches, stops and the warning message is displayed. The battery is less than a year old and has never been flat to the point that the car won’t start. The day after charging it was showing 12.8v.

Trying to fix this I have made sure the boot compartment cover is fitted correctly, also trying with it stowed to make sure the car detects that it isn’t deployed and shows the warning. That’s all fine. I went through the steps in the manual to reset the roof (twice), opening the valve on the pump, waiting for the pressure to drop, folding the roof up, releasing the rear cover, and stowing it correctly, closing the pump valve and letting the cover rest closed. With the roof stowed and holding the close button, the roof closes perfectly and latches into place. However after this reset, opening the roof still fails. It winds down all of the window, unlatches, pops up about two inches and stops, followed a few seconds later by the roof not latched warning. Pressing the close roof button and the roof drops and latches into place, the windows go up and the warning clears.

I’m at a bit of a loss what to check next. There are no codes stored apart from the intermittent roof not latched error which clears when reset. The pump reservoir shows the fluid at the max line, with the engine off (ignition on) the battery is above 12v and at idle the voltage is above 14v.

Can anyone help with some suggestions on what to check next please?

 

The battery NEEDS to be at 12.6 as a minimum after sitting unmolested for at least six hours. Good on you for charging it overnight, but it's still 12.6 you need to have. Always. Measured at the battery, car completely off.

 

I’ll add that also, every time the battery is disconnected, you have to reset the windows which it sounds like you did, and the roof.

This happened to me a week or so ago after I disconnected my battery.
. When it pauses after unlatching, continue to hold the button for a while. It will start going again.
That was my sign it wasn’t reset.
if it doesn’t, then it may be something else.

 

Thank you for the replies. I've been outside and removed the trim to measure the voltage at the battery (still connected to the car) and its 12.64v. The car has been sat for around 7hrs at this point but I've connected the C-TEK to the battery directly and put it in recon mode to see if that helps at all.

 

Did you test long holding the open button?
Maybe 20s or so after it stops moving?

 

A little update for today. The battery was left on a recondition charge over night and was 13.56v when tested this morning. I tried the roof again with the diagnostic tool plugged in and I can see that the sensors are responding correctly for the luggage sensor, window open status, the roof latch status, and I can see the roof control module commands the bow in and bow out solenoids to trigger, but the roof refuses to move after the initial unlatch. With the engine running the lowest voltage shown on the diagnostic tool was 13.6, however reading the voltage at the battery shows it to be 14.1 – 14.3v.

I left a thermal camera in the boot / trunk to record the pump. When I first press the button to open the roof you can hear the pump kicks on for a few seconds, then two of the solenoid valves (forward most, then the one closest to the inside of the car) quickly get hot.



Is it likely that one of these solenoids has failed, maybe the one responsible for the initial lifting the front of the roof?

I also tried holding the roof open button in for a minute but nothing happened.

 

I’ve had some time to look deeper into the issue and I think I’ve found the problem. The “Top latch sensor” is remaining in an Active state after the roof has unlatched and lifted a couple of inches away from the car.



Does anyone have any experience in diagnosing this sensor? Is this in the actual roof or is this in the top of the window frame? Also would anyone know if the wiring for this sensor runs along the left or right side of the roof?

 

Not sure about the sensor location, but there’s a wiring loom along the left side of the roof, and the bend at roughly the C-pillar location has been known to have wire breakage and cause opening/closing issues.

 

PM me if you want more information but I can tell you what I think is happening to you. In my car the wire running through the top, where it has a hard fold and unfolds, eventually metal fatigued and developed an intermittent connection. I took photos of the problem, and fixed it by replacing that segment of wire with “robot wire” which is 1000 strands and very flexible and won’t metal fatigue.

 

I thought I would post an update to my roof saga. Sunday afternoon I manually opened the roof with the diagnostic machine connected so that I can monitor the top roof latched sensor, and sure enough it remained active with the roof open. I had a look down the hole the guide pin slots in and I could see the sprung arm for the sensor slightly off to one side (left hand latch bracket above the windscreen).

I tried poking a screwdriver in the hole to move the arm but I couldn’t get the sensor to change state, then while doing this next door came over for a chat which turned into a two hour long catch up and when I got back to the car the sensor was showing as Inactive all of its own accord.

Once again I poked the screwdriver in the hole and this time I could see the sensor change from Inactive to Active. So somehow it’s fixed itself. I put several squirts of contact cleaner in the hole to clean it all out and gave it a final spray of PTFE just in case the arm was sticking, but since then the roof has been working fine.

I’m not sure where that leaves me, either this was a very cheap fix or there is a deeper wiring fault / sensor issue that will come back to haunt me later. I guess I will take the win for now.

Thank you for all of your help and suggestions. Maybe this will help someone else if one day they find that their roof will close fine but refuse to open after unlatching.

 

Thank you for following up.
With cars this old, I feel like taking the win is the best option.
Worst case it kicks $$$ down the road.