Convertible top with no signs life...

[bmwzzzz]

Hey all,

I recently picked up an '03 Z4. Every thread about top issues mention error lights that show when a button is pressed. In my case, there is no light shown or sound at all.
I press the button and absolutely nothing happens. I checked the three fuses that are responsible for the top, all checked out. I even tried using twisting the key in the door lock, which from my understanding, lowers the windows and will also lower the top. The windows went down, but again, nothing from the top.
The sellers had noted that the battery had gone dead for a period of time when they hadn't used the car much over Covid, and I've tried the relearn process for the pinch protection with the windows. I've confirmed the rear compartment tray is lowered, so that is not preventing this.

Is this an issue with the top control module? Maybe a power or ground issue? The weather is getting nice and I'd love to be able to use this feature, any ideas on what to check?

 

[bigwinn]

Deffo worth swapping the module out as I’m seeing more and more fail

Where you based?

 

[enuff_zed]

Hi. I’m assuming you are the person Paul told me about? Did he give you my number?
I too am thinking swap the module first,

 

[Haro]

Try resetting the windows, might be the problem if it's been sitting.

 

[enuff_zed]

Try resetting the windows, might be the problem if it's been sitting.

He says he’s done that

 

[bmwzzzz]

Hi. I’m assuming you are the person Paul told me about? Did he give you my number?
I too am thinking swap the module first,

I don’t believe I’m the same person but I’ll definitely send a DM. It’s my understanding that the modules need to be programmed to the car by the dealer? Not the end of the world but I’d love to solve this without including those hourly rates…

 

[bmwzzzz]

Where you based?

I'm based in Northern California, South Bay. Water intrusion shouldn't be an issue out here but I won't rule it out.
From my impression there would be at least some light if something mechanically was wrong.

 

[bigwinn]

Where you based?

I'm based in Northern California, South Bay. Water intrusion shouldn't be an issue out here but I won't rule it out.
From my impression there would be at least some light if something mechanically was wrong.

No- all the symptoms you describe point to actual experience of the module failing

 

[bmwzzzz]

No- all the symptoms you describe point to actual experience of the module failing

Right, it’s an electrical/module issue rather than mechanical. I’ve got a BMW code reader on the way to see if anything is thrown there; if not, looks like it’s a job for a local shop to diagnose.

 

[enuff_zed]

Hi. I’m assuming you are the person Paul told me about? Did he give you my number?
I too am thinking swap the module first,

I don’t believe I’m the same person but I’ll definitely send a DM. It’s my understanding that the modules need to be programmed to the car by the dealer? Not the end of the world but I’d love to solve this without including those hourly rates…

Replied to your message. Didn’t realise where you were. Swapping the module is pretty easy and if needed we can advise on compatible replacements to get from eBay.

 

[DMike]

Where you based?

I'm based in Northern California, South Bay. Water intrusion shouldn't be an issue out here but I won't rule it out.
From my impression there would be at least some light if something mechanically was wrong.

No- all the symptoms you describe point to actual experience of the module failing

Bigwin’s way more experienced with tinkering these and probably right about the module but I’ll add an easy one. Maybe a totally silly question, OP, but you did have the ignition on when trying the open button?

To test the behaviour caused by the shelf microswitch, which occasionally fails too, tested on my ’05, with no issues, to raise the shelf and
- turning key in door lock, with a similar beaviour to yours: Windows went down, no lights from the panel, nothing from the roof latches or motor
- with ignition off, no response to the panel buttons, no lights
- with ignition on, no physical response from roof or windows, BUT the orange light next to the button was lit as long as pressing the button

 

[Jas- USA]

Totally rule out the Microswitch by checking that the rear panel is actually seated correctly and making sure it's making contact with the slot for the microswitch. Consider jimmy-rigging (by-passing) the Microswitch, which should totally remove it as a possible source for your issue.

When my microswitch had issues, I had nothing, when pushing top down.

If the above doesn't work. Go to the convertible controller and make sure the plug is totally seated into the unit. Clean both of the contacts of the plug & plug in for the Convertible controller with Electronic contact cleaner.

If this doesn't work, consider a used convertible controller. I believe these do not need to be mated to the car.

 

[bmwzzzz]

but you did have the ignition on when trying the open button?

Yes, I've tried it while running and parked, along with all other key positions to be sure.

Consider jimmy-rigging (by-passing) the Microswitch, which should totally remove it as a possible source for your issue.

I'll give this a shot. And to confirm, the switch being bad would result in no lights when pressing the top button, instead of some error light?

 

[Jas- USA]

but you did have the ignition on when trying the open button?

Yes, I've tried it while running and parked, along with all other key positions to be sure.

Consider jimmy-rigging (by-passing) the Microswitch, which should totally remove it as a possible source for your issue.

I'll give this a shot. And to confirm, the switch being bad would result in no lights when pressing the top button, instead of some error light?

I didn't have either lights or movement, nothing. There's a youtube video on jimmy-rigging the switch, just search under z4, e85, microswitch. I can't tell you it's the problem, but I also won't say that it isn't.

 

[bmwzzzz]

Okay so I picked up the trusty C110+ to scan codes. Thankfully there's a whole section on the convertible top module. It seems like the module is responding fine, so I am assuming that rules it out as bad.
The information in the live data readouts is odd.
The first thing I noticed is the position of the top is labeled as "implausible":

Then the compartment lid is supposedly "locked" on the right side, and "unlocked" on the left...

And then some general codes that were stored, I cleared them and they haven't come back, but that might be because the top hasn't entered a movement cycle to retrigger them?


I've tried to lower the top manually, but the red hook on the hydraulic release is broken and it seems to be pretty well seized.
I have seen the posts about how these sensors sometimes break off or wires shear with age, but I haven't found a manageable way to check these sensors. Any advice is much appreciated!

 

[Jas- USA]

1st, can you manually release the tops frame from the windshield? If you can get the frame released from the windshield, you'll then have to reach the top's motor/pump thru the trunk and bring it, the motor, to the trunk. Once you have the motor in the trunk, you'll put the motor in a bucket and loosen the banjo bolts for the hydraulic lines which will depressurized the system and allow you to move the top and begin looking for your issues.

Go to youtube for go-by's on reaching the motor thru the trunk.

 

[bmwzzzz]

So I've tried a bunch of times to get the top down manually. My red bowden puller is missing so I opted for vice grips to apply a bit of tension. I tried a number of different tensions on the cable since I don't know exactly how far it needs to come out, but this still made no difference. The allen key allows the top to release from the windshield, but I can't move it back more than 5-8 inches.

I've replaced all three fuses with new ones, and the only new bit of info mirros another thread with the same symptoms. Replacing fuse 31, the orange and red lights flash once. But still nothing new beyond that.

I saw comments about the possibility of the hard top sensor disabling the button, but from the code scanner readout, the hardtop shows it's correctly "not mounted".

With the top stuck up, I can't see a way to verify the integrity of the hall sensors. I guess the next move is a new roof module as the wiring diagrams show everything runs through it. I am hoping to be proven wrong as all the data readouts work from the module, but its the next low cost item before things go totally nuclear with repairs.

Time to browse eBay...

 

[enuff_zed]

Don't try to force the roof back if the manual release isn't working or you could burst a pipe.
Still pretty sure it's the control module.
An easy swap out.
Do that first before you start getting into too much complexity.

 

[bmwzzzz]

Well I'm disappointed to say the least. Drove 300mi/5hrs round trip to get a module. Nothing different once it was installed. Code scan tool shows the same readouts; buttons are pressed, all conditions are met, but the roof location is still "Implausible".
So I am fairly certain it's the simple Hall sensor or a wire in the top mechanism, I just can't find a way to validate this with the roof stuck fully up.
Still no red or orange error lights, no activation of motors, nothing.
Feeling pretty defeated at this point. I really don't want to cut hydraulic lines without having a garage or workbench to repair later on, I don't really know what the next step is now.

 

[smorris_12]

Someone will hopefully correct me if I'm wrong but, if it was me, once the claws were undone I'd assume I could simply run power to the hydraulic motor (or relay?) directly to make it operate. Since you obviously won't have relocated the motor, I'd do this thru the module connector.

FYI, the Bowden cable only pulls out about 1/8" to release.