Weird Soft Top Problem

[BumpyZ4]

I have a 2003 E85 that is new to me. The top had two leaking hydraulic hinges so I never saw the top work. I had the hinges rebuilt by Top Hydraulics and relocated the pump/,motor to the trunk. When I try to operate the top (up or down) in only moves a couple of inches when I push the button. Then I have to release the button and push it again and it moves another few inches and stops. I have to repeat the cycle until the top is either fully open or closed. The top worked fine on the ground just putting battery power to the motor before I reinstalled it in the car.

Any guesses??

 

[tomrdy]

Can you hear the motor keep spinning when it stops moving? If so, maybe there's air in the hydraulic line?

 

[BumpyZ4]

The motor only runs for a second or two. Then I have to release the button and push it again and it runs for another couple of seconds.

 

[enuff_zed]

How easy is it to move by hand? Have you tried?
Sounds as though it may be very stiff and the motor is feeling the resistance and thinking it has got to the end of its movement?

 

[Number5]

Sounds very much like the roof ECU or a sensor issue.
Can’t be hydraulic pressure or it wouldn’t move at all. The motor is starting by itself each time so that’s ok so I’d lean towards the ECU not sending a continuous 12v to the motor. This can be caused by issues with the hall sensor loom confusing the ECU

 

[Number5]

Sounds as though it may be very stiff and the motor is feeling the resistance and thinking it has got to the end of its movement?

The motor doesn’t sense resistance. The stop command only comes from the 2 hall sensors which are at either end of the cycle and are ‘position detectors’

When the hall sensors engage the ECU then changes to stop the hydraulic motor and starts operating the claws.

This is how the claws operate even when you’ve lifted the roof manually. As soon as the roof is an inch or so from the windscreen, the ECU knows to start the claws and lock it down

 

[enuff_zed]

Sounds as though it may be very stiff and the motor is feeling the resistance and thinking it has got to the end of its movement?

The motor doesn’t sense resistance. The stop command only comes from the 2 hall sensors which are at either end of the cycle and are ‘position detectors’

When the hall sensors engage the ECU then changes to stop the hydraulic motor and starts operating the claws.

This is how the claws operate even when you’ve lifted the roof manually. As soon as the roof is an inch or so from the windscreen, the ECU knows to start the claws and lock it down

Fair enough.
Wasn't completely au fait with the system as you quite obviously are.
Appreciate the clarification, ta.

 

[Number5]

Fair enough.
Wasn't completely au fait with the system as you quite obviously are.
Appreciate the clarification, ta.

No worries. I can understand your logic, but when I've dislodged the 'down' sensor during relocations, you then find the hydraulic motor just keeps going and going until you take your finger off the button. It does this as nothing's telling it to stop, even the the roof is firmly in the boot.

 

[BumpyZ4]

Fixed it! I disconnected the battery overnight reconnected today and the top works beautiful. I can only assume that the Top module was confused for some reason. Thanks for all of the replies!

 

[tomrdy]

Fixed it! I disconnected the battery overnight reconnected today and the top works beautiful. I can only assume that the Top module was confused for some reason. Thanks for all of the replies!

The tried and true "engineer's" fix - turn it off and on again :rofl: glad that sorted hassle free

 

[Aleita]

Fair enough.
Wasn't completely au fait with the system as you quite obviously are.
Appreciate the clarification, ta.

No worries. I can understand your logic, but when I've dislodged the 'down' sensor during relocations, you then find the hydraulic motor just keeps going and going until you take your finger off the button. It does this as nothing's telling it to stop, even the the roof is firmly in the boot.

Maybe I have issue like this. My 2004 z4 soft top won’t operate latching/unlatching from windscreen.

But front electric motor work fine locking rooftop in full opened position ( behind seats) so i don’t think this motor is broken.
I’ve checked also the hall sensor. It’s ok.
This think is driving me crazy

Please help