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Convertible Stops at Trunk Lid

29K views 58 replies 10 participants last post by  tks 
#1 ·
AFAIK the trunk lid raising is controlled by the GM module, not the CVM module. If the lid won't raise I'd suspect the system doesn't know the lid unlocked and stops operation.

Does the top work in reverse? Ie if you lift the lid, manually fold the top into the storage area and rest the lid ontop can you:
1. Push the open button to get the lid to clamp down?
2. Push the close button to get the lid to raise and start closing?

Please start another thread rather than clutter this sticky since your problem appears unrelated... at this moment. There's been a couple members recently reporting issues with the top stopping in similar positions, search, hopefully they checked in with solutions.
Continuing a thread Taylor asked me to move to another thread. I've been trying to fix this for over 6 months now. Made past threads here and on other forums too but no one had this specific issue (most had wiring harness issue which caused the top to stop well before the lid).

In the sequence of the top opening, it stops where the trunk lid is supposed to open and just hangs there (no blinking light until I let go of the button). The lid itself unlocks fine and I can open it with my hand. I was thinking it could be a frayed wire in the CVM, but Taylor said the lid is controlled by the GM module. Where is that located? I will update the thread once I check tomorrow if the lid opens if I manually put the top into the trunk.
 
#2 ·
In the sequence of the top opening, it stops where the trunk lid is supposed to open and just hangs there (no blinking light until I let go of the button). The lid itself unlocks fine and I can open it with my hand. I was thinking it could be a frayed wire in the CVM, but Taylor said the lid is controlled by the GM module.
I would say that taylor192 has put you on the right track. Since there is no light blinking before you let go of the button, that means there is no "wrong" signal going to the controller - it likely hasn't received the signal yet that the lid is unlocked and thus will not proceed with pressurizing the tonneau cover lift cylinders.

It would be much more unlikely for the following, other possibilities to occur:
1) The controller gets the correct signal but doesn't proceed
2) The controller passes the signal to the valve pressurizing the tonneau cover lift cylinders but the valve doesn't open

Klaus
 
#3 ·
avneet,

Please familiarize yourself with the PDFs that describe how the top operates. Here are the steps to open the top:

• Top Switch Pressed “Open”
• CVM activates the top lock motor and the top is unlocked and raised past the tension point (LED switch flashing).
• At the same time, the CVM signals the GM to lower the windows (if closed) for approximately 1.5 seconds.
• Top lock motor is switched OFF - signal from cowl released hall sensor (S145).
• CVM activates hydraulic pump and switches the tension bow solenoid (V4) to raise the tension bow.
• Tension bow is raised to its vertical position - signal from tensioning bow angle hall sensor.
• CVM signals GM to unlock storage compartment cover.
• Storage compartment cover unlocked - signal from motor hall sensor (S700) - storage cover lock motor is switched off.
• CVM receives status of cover lock from GM over K-bus - switches storage cover solenoid (V1).
• Storage cover raised to its open position - signal from cover hall sensor (S188).
• CVM switches to the lowering solenoid for the tension bow (V3) - top starts lowering into storage compartment.
• CVM switches the main pillar solenoid (v2) - top is fully lowered into storage
compartment.
• CVM switches solenoid for top cover (V1) - cover is lowered - signal from storage cover lock hall sensors (S161 and S158).
• CVM signals GM to lock storage compartment cover.
• GM activates cover lock motor - cover is pulled closed by lock assemblies.
• GM switches off lock motor - signal from motor hall sensor (S700).
• CVM switches off hydraulics and LED.

Your top seems to get stuck at the underlined step. This is why I wanted you to try the 2 things I listed. #1 performs essentially the same step, just to lock the storage lid. #2 performs the exact same step to unlock the lid before opening.

Please report back once you've tried both.
 
#5 · (Edited)
Sorry I took so long. It's been 100 degrees here these past few days so I was waiting for the coolest time I could.

1. I tried this. I held the open top button until the part it stops where the lid is supposed to open. I turned off the car and proceeded putting it into the trunk and closing the lid. I first lift it slightly open an inch, then pressed the open top button. Nothing happened at all (no blinking lights either). Same thing when I closed the lid completely. Didn't lock. It seems like it thought the sequence was done.

2. When I pressed the close top button, I could heard the sequence start with the lid lock opening. From there nothing happened. Lid still wouldn't open.

3. Also to note. When I first tried to open the top using the switch for step one: When it reached the lid opening part, I just unpressed the button first and walked over and lifted the lid. When I let the lid go, it stayed up at about a 35-40 degree angle (but not as much as it would on it's own without touching it). Only when I turned off the car to put it in manually did it fall.

Cinredman. I will check that next when I get through this 100 degree weather. Though I have never had any liquid leak out anywhere that I've seen. Assuming I'll have to take my trunk apart. Spent so long mounting a fire extinguished to the left side. Just my luck.
 
#6 ·
That sucks. I think you're going to need a shop or dealership to monitor what is happening with the top.

Since the back window raises during the top open sequence, I would say it is probably not a hydraulic problem, yet it would be good to rule that out by checking the fluid level. The level must be checked with the top down, and since the lid won't lock down to complete the top open sequence you'll have to carefully open the trunk to avoid hitting the storage lid.

You are the 2nd person to have this issue, not sure what happened with Ruslan, he stopped posting.

FYI the GM module is known to fail. People have reported issues with door locks and windows related to a failed GM module... yet I have no clue how to test that.
 
#7 · (Edited)
That sucks. I think you're going to need a shop or dealership to monitor what is happening with the top.

Since the back window raises during the top open sequence, I would say it is probably not a hydraulic problem, yet it would be good to rule that out by checking the fluid level. The level must be checked with the top down, and since the lid won't lock down to complete the top open sequence you'll have to carefully open the trunk to avoid hitting the storage lid.

You are the 2nd person to have this issue, not sure what happened with Ruslan, he stopped posting.

FYI the GM module is known to fail. People have reported issues with door locks and windows related to a failed GM module... yet I have no clue how to test that.
Do you mean back lid? It doesn't open on it's own, but only after I lift it it stays. If you do mean windows, they go down a bit like they are supposed to when you first start the sequence.

Also thanks a lot for your help guys. I really appreciate it. I think this will be the end until I have a new idea in the future. I was being told by the dealer that anything to do with the top usually costs over a thousand dollars. That's just not something I want to spend on this car when I'd rather fix real mechanical issues like wheel barrings (and not spend more than the car is worth after all repairs).

I was reading the pdf and can't figure out where the GM is located. Do you think it could be worth changing that and seeing what happens?
 
#9 ·
I'm having the same symptoms you're having man. Hoping that something is figured out here on this thread. I've had the problem for I while. i get a strong feeling it's the GM module because of the windows acting up as well. The gm module in the verts is located behind the arm rest in the drivers side back seat. It's not very difficult to access.
 
#10 ·
i get a strong feeling it's the GM module because of the windows acting up as well. The gm module in the verts is located behind the arm rest in the drivers side back seat. It's not very difficult to access.
Where?



The GM5 module is located behind the glove box. This guy offers a repair service so I would start with him and see what is different between a GM5 module for a coupe and vert: http://www.bmwgm5.com/

The coupe does not have the rear window relays, does thevert have something extra not pictures or labeled?


 
#12 ·
My mistake. I mislead you. I was thinking the CVM which is the hidden white module to the left of the black amplifier in your picture. The GM module is in the glove box behind the fuses or above. Can't remember exactly. The website you linked is vouched for based on my research on this site. I think the guys name is scott.
From my understanding of the GM module there are different relays on it controlling different things meaning you can have one problem without having another.
 
#18 ·
The BMW manuals say otherwise. The GM controls locking/unlocking the lid, not raising/lowering it.

We know the motor under the rear seat controls locking/unlocking the lid, maybe it has some electronics in it that communicate with the GM.
As I said before, your best bet is to find another vert owner locally and try swapping some parts. At the point it is stopping it could be one of:
CVM not operating correctly
GM not operating correctly
Lid motor or sensor not responding correctly
Latch sensors not responding correctly
Hydraulic solenoid not operating correctly to lift lid

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#19 ·
I know for sure it's not the motor under the back seats. Already took that apart and it works fine. The latch unlocks as it should from that motor. It's the motor the raises and lowers the latch that never kicks on to raise the latch.

Page 10 in PDF:

During the soft top operation, when the tensioning bow is raised or when the top is in the storage compartment, the CVM signals the GM over the K-Bus to unlock the storage compartment cover. The GM activates the lock motor and the motor turns 180 degrees to unlock the cover latches. The motor always turns in the same direction to unlock/lock the cover.

Once the motor has turned 180 degrees, the hall sensor (S700) input signal will cause the GM to switch off the motor. At the same time, the GM will signal the CVM to continue top operation.
This seems to be where my issue is. It unlatches perfectly, and then nothing happens for the lid to start raising. I wondering if Hall Sensor S188 could be the problem. Page 16 of the PDF manual states this is what causes the lowering or raising of the lid.
 
#20 ·
I know for sure it's not the motor under the back seats. Already took that apart and it works fine. The latch unlocks as it should from that motor. It's the motor the raises and lowers the latch that never kicks on to raise the latch.

This seems to be where my issue is. It unlatches perfectly, and then nothing happens for the lid to start raising. I wondering if Hall Sensor S188 could be the problem. Page 16 of the PDF manual states this is what causes the lowering or raising of the lid.
The hall sensors rarely go bad, they are just glorified magnets, yet they are cheap and easy to replace. The hall sensors are all the same, I found them without the connectors for $20 on the ECS Tuning site.

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#21 · (Edited)
I bit the bullet and made an appointment for next Thursday with the stealership to diagnose the problem. I'll then report back and try to fix the issue myself and save the major portion they would ding me on. I figure diagnosis should be a couple hundred on the highest side (they probably will assume they can keep it lower and ding me on repairs not knowing I'm repairing it myself).

Hopefully my cost can at least save others from costs in the future with this same problem.
 
#22 ·
Ruslan is having a very similar issue and has sent me a few videos via PM as he tries to diagnose it. This is the latest video after the pump was replaced:

http://www.youtube.com/watch?v=NL376HYG8as

It appears the main lift cylinders are not working to lower and raise the top. At the end of the video you can see the top struggling to raise out of the top. The system is not leaking fluid, and there are no CVM codes, so I'm stumped what this could be. My best guess would be the solenoid that controls the main lift cylinders is not working properly... yet to change it is a lot of work just for a "hunch".
 
#23 ·
details about the valve block



The valve blocks fail fairly rarely, but that is a possibility. If there is a small bypass inside the valve block, then there may not be enough pressure left in Ruslan's case for the main lift cylinders to lift the top when it is close to the windshield. That's where the highest amount of pressure is needed. It could also be an internal leak in one of the main lifts, but those are less likely than an internal leak in the valve block.

Lifting the rear bow or the case cover, or even lifting the top from the stored position is much easier for the system.

One more piece of info: if people have waited too long to have their hydraulic cylinder seals upgraded, then it is possible for the system to suck in small remnants of the seals and get them lodged inside the valve block. The effect of this is normally a very slow movement in a specific part of the top's sequence.

Ruslan should play "musical solenoids": swap all three solenoids in the valve block and see if the same problem persists... :)

Klaus

www.tophydraulicsinc.com

 
#25 ·
She's there right now. Dropped off at 12:00pm. So far I've been charged for one hour of labor just under $200. I hope that finds the problem, but he said convertible tops sometimes need more time. Hopefully will know more tomorrow. Until then, I'm not liking the 2012 535i I got as a loaner. It's huge! My car is so tiny compared to this thing. Though I LOVE the features.
 
#28 · (Edited)
So I'm waiting at the dealership for them to put it back together. They still aren't 100% sure, but they narrowed it down to 2 possibilities. ($450 per fix) cost to fix each. I said no way of course, esp since they aren't sure.

1. The wire harness in the trunk bend on the right shows signs of frayed wires when wiggled. They are sure wires are broken in there (though they never opened it). Part of the $450 is to open it.

2. They showed me the hydraulic fluid motor for the trunk lid which is besides the hydraulic fluid (post a pic later for an idea of where it is). They know it works, but its not getting enough power to lift the lid. They will check here next if the first fix doesn't work. But that motor seems to be the problem. The question is why it isn't getting the necessary power (since they aren't sure if option 1 is the reason).

They think the reason the motor isn't getting power is because of the wire issue. I'm going to fix that myself with a soldering iron. Also found out my control arms are dangerously bad. I knew they were since my car shakes whenever I turn at fast speeds, but mechanic told me they won't last much longer (ready to break). That I'll take to my local mechanic.
 
#29 ·
Ruslan tried a different hydraulic pump with no success... I think, hopefully he comes in.

Klaus suggested playing musical solenoids, maybe the solenoid that controls lifting the top is bad. There are 3 solenoids on the valve block, switching them looks easy.... once the top is removed from the car.

It's too bad you're not closer, I'd help you give it a shot.



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#30 · (Edited)
I opened up the wire harness in the trunk, and oh my god I've never seen so many open wires. I don't think there is one wire that is not frayed. I'm going to try and solder all these by the weekend (hopefully all today). I can't believe there haven't been any major shorts (unless the lid not opening is one haha). Look at this picture and tell me you aren't as surprised as I am.

I'll definitely be checking all my fuses after I finish to see if any was blown from before.

 
#31 ·
Sadly that was not it. It only fixed my trunk not closing, trunk lights, and license plate lights. Hard not to feel down. But I will strive on! Next time I can get around to it, I'm taking apart the trunk and scoping out the hydraulic pump (since dealers pointed to it anyway).
 
#35 ·
If your issue is the same as the video I posted then the hydraulic pump has already been tried. Don't waste your time and money.

I get you're trying everything to avoid removing the top from the car, yet the valve block and solenoids are your best bet to look at. Find a friend and pull the top, it's not that hard.

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#33 ·
If fixed: If I closed the trunk with my doors unlocked, it kept opening the second it would latch automatically. Only way around this was to lock the doors first and then shut the trunk. Also the trunk would open if my doors were unlocked and I was driving over even the slightest bump. Plus smaller issues like the lights in the trunk not working and the license plate light not working at night. I suggest any e46 owner to check those wires. You don't have to cut that harness like I did. I realized after it just disconnects from the trunk easy. Check your wires for sure.
 
#36 ·
No my problem isn't like the video. His lid actually moves. Mine doesn't move at all after the back part (u shaped) part lifts up. I can lift it up with my hand during the sequence, and when I let go it drops back down about half way.

jjamal, it's actually in a really simple spot. Just open your trunk, and look at by the right hinge connecting the trunk to your car. There is a black tubing going from the trunk to your car. You can pull out the part connected to the trunk to see the wires. They should be broken about halfway down that black tubing.
 
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