A4 2005 Cabriolet (B6) Top issues

[JGMachine]

Hi all.

I am new user.
Got my first Audi almost two years ago it lived in the garage while I did timing, head gasket, coils and plugs, water pump, thermostat etc... whole nine yards.

Ran into my first big headache the Top refuses to work.

Here are my facts
-does tell me soft top not secure every time i drive off
-I have no error codes via ECU.
-I have no errors on the dash such as "soft top can not be used" or "please lower storage shelf"
-I bypassed the storage shelf by jumping the sensor wire.
-I have inspected the top locking motor and the microswitches in the a pillar that detect the top being locked.
-I have two different Convertible top modules.
-The top knows when it's down and the dash light goes away when I lower the top manually and lock the compartment manually
-The light stays flashing when it's up and closed completely.
-the only thing that happens is that I can audibly hear the the clicking of the relays inside the CCM.
-***Forgot to add I already fixed the broken wires in the driver door.

-No other operations happen such as unlocking / window motions / hydraulic operation.

-My best assumption is that the top locking motor is not operational. But have no idea on how to confirm it's operation.
-Or even the switch itself but I don't believe so because the relays audibly work.

Any assistance would be greatly appreciated.

[EuroxS4]

you will need vcds to perform any sort of diag on this system as it has a total of 12 if not more microswitches to tell the module where it is. You most likely have a microswitch thats failed and reading incorrectly. Either way your gonna need a vcds and have a good understanding of how that system works. Then you can look at MVB to see which switch is not reading correctly.

A better more simplified decription of the issue would be best. It looks like the top is working but your getting a error message that its not secured. If different please just specify what its actually doing.

[JGMachine]

Thank you so much I am unintiated in Audi diagnostics Im using a basic ELM 327 from maybe 8 years ago. It reads and resets codes but maybe its not able to read the Audi specific codes. In reality nothing happens when I try the system other than relays closing inside the CCM. Whether the top is up or down.

When driving error code soft top not secured comes up even though it's fully secured and locked with the emergency key, the top lights flashes constantly un less I lower the top and Lock the compartment, then the warning light dissapears.

I will be downloading VCDS and hoping that can point in the right direction.

[EuroxS4]

Sounds to me like you have a issue with one of the latches for the top cover as this is a common issue on those cars. But again you need something thats capable of looking at MVB in order to determine the cause of the failure or which component has failed.

[f4i-pilot]

I had mine interrupted in cycle a few months back, did some of the same things your are saying
Audi tech buddy told me to do a complete manual down and up cycle to “reset” it
Not sure what it did, but it’s worked ever since

Whether it’s down and locked it up and locked he said to do a full cycle with key on

Just my .02


Sent from my iPhone using Audizine

[JGMachine]

Turns out you were right I had no top compartment motor to lock / unlock it (V222)

Lucked out I found a blue B6 at LKQ an hour away went up there scooped up a motor and better condition back seat. I installed the motor and it started to work the top unlocked and I heard the hydraulic system motor start to operate but nothing happened after that the bows did not move the top at all. It did close and Windows operated but no hydraulic action thus far.

This is what I know the G356 sensor had one leg broken and I used lacing wire to hold it in place to test but will be ordering a switch soon. When I do hold it longer to see if the moves it sets the code and i have to do a full reset with the key in that fixes it and i can try again.

I am still receiving the following codes
02000 implausible signal
01986 G356 intermittent signal

How do I go about determining the state of the electric pump for hydraulics. I do own the Bentley hard cover service manual and it contains the cabrio addendum. But it's nice to hear from first hand experience.

Thanks

[EuroxS4]

the 2000 implausible signal fault is from you holding the switch for extended period of time I would not worry about that. I would try to figure out you g356 fault. either sensor or wiring. I think 10 out of 10 its the sensor. I work on these cars everyday and this is a common failure. As are hyraulic pump relays normally the best way to diagnose that is to see if the pump will pop the top and stop. Tall tale sign of 2 bad relays. However in your case replaced G356 and report back.

[JGMachine]

More updates I figured out the problem with the motion mostly I had cleaned the electric motor and inspected the brushes but never made note on the orientation of the motor. So I flipped it around and that gets the top moving but the top compartment does not unlock or move the top is just waiting there for the compartment. If I manually unlock and raise the compartment it will finish the cycle and stow the top.

When I try to close everything seems to go as ordered it unlocks and raises the compartment lid, top comes up and then it does not lower the compartment. (Cant manually push it either) seems like the relay is getting stuck switching between motions. Not setting any fault codes in VCDS right now. So close but this one has me perplexed.

I wrote this reply before reading yours I was thinking that relays were not directing the flow properly but the compartment opens and closes it justs does not do it while the top is up and waiting.

[EuroxS4]

Was G356 changed already?? Or still waiting for the part?? That sensor need to be ok and reading in order to tell the module in which position the top is in. Change sensor first and report back. If still not working. Will need to check hall sensors for top compartment lid.