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Discussion Starter #1
Hi All,

I currently use Multiecuscan 4.0 with the green and red leads to generally interrogate the system and more to reset airbag as this is failure for mot's.

However i now have a problem with the electronic hood, flashing light for 10 seconds when starting and then no response.

The hood can be closed manually using the electronic buttons behind the seat for the release and opening of box.

So thought i'd get the purple lead to diagnose the hood ecu, when switching on the ignition and then pressing 'Y' to start the diagnostic, the key code light on the dash almost comes on immediately, this i think bars the connection and results in not finding the ecu!

Has anyone had the same problem and if so did anyone find a way around it?

Many thanks

Wilywalt
 

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I have tried connecting the same way with no luck. I think the only way is to connect directly to the hood ECU with a 3 pin connector but I haven’t tried this yet. I had a similar problem; nothing when I pressed the button but if I used the manual switches and lifted the back of the hood, it would start working. It would close up to the point when the back of the hood locks and stop again. The issue was solved by adjusting the length of the rear pins. One had about 4-5mm of thread showing, the other had none. 5 mins and a 17mm spanner and I adjusted one so they both had the same amount of thread showing. Seems to have done the trick.

The nut at the back was loose and the worm drive must have screwed the pin as far back into the frame as it would go. I’m guessing that it wasn’t sticking in the hole enough to operate the second microswitch and tell the ECU that it was locked. Because it thought it wasn’t locked it didn’t continue with the cycle to close the hood. On opening because it thought one pin was locked and one wasn’t it got confused and did nothing until I used the manual switches and it knew both were unlocked and could carry on.
 

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I had so many hood problems over the years it would work 1 time in 20, lights flashed like yours on many occasions. I tried everything but gave up as using the manual buttons was easy enough. I still tried the auto switch every time just in case - but 1 in 20.

My alternator died so I had it replaced about 2 months ago

Once that was done the first time I tried the hood it worked (I always have the engine running when operating the hood). Since then it has worked EVERY time - seriously the weather has been so good that it has been up and down every day for the last two months without a hitch.

My point?

I am no mechanic but maybe, just maybe, it needs a full (rather than acceptable) output from the alternator to ensure satisfactory operation?

At the very least consider it may be an electrical rather than mechanical problem.
 

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Discussion Starter #5
Success! - And all due to a no thread - Electric Hood Microswitch

Hi NellytheRoc,

Well, all i can say is a 'Big Thank You' - You hit the nail on the head though in this case the threaded bolt!

Having spent a year with a roof that had become manual, it is now operating as it should be. What threw me was that one side of the rear pins (Drivers side) had a nut and the other side hasn't. looking further into this, these are self tightening threaded bolt/pins which don't really need a nut!

Sure as anything the bolt on the passengers side was not showing any thread, hence this was not catching the micro switch leaving the ECU in a state of not knowing whether the roof was closed or not!

In the process of fixing this i also renewed the hydraulic fluid with what i understand is the correct specification - ISO VG 22 - So now the roof is closing sweet!

Happy Driving once again! Whoa!
 

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Hi NellytheRoc,

Well, all i can say is a 'Big Thank You' - You hit the nail on the head though in this case the threaded bolt!

Happy Driving once again! Whoa!
You’re welcome. I’d have to open my own brewery to pay back all the people I owe a pint or two on here that have helped me with my cars. Glad I could help.
 

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could someone post a pic of these pins as this sounds like an issue i am having at the moment
It’s the two pins that stick out under the rear window that lock into the top of the clamshell. There are two microswitches. One tells the ECU that the pin is in the hole and to start the motor to lock it in. The second microswitch operated when the pin is fully in the hole and locked. As a fail safe the motor stops after a set amount of time if the second switch hasn’t been activated. If this happens, the ECU won’t start the next part of the closing cycle. I’ll take a pic tomorrow if you need it.
 

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It’s the two pins that stick out under the rear window that lock into the top of the clamshell. There are two microswitches. One tells the ECU that the pin is in the hole and to start the motor to lock it in. The second microswitch operated when the pin is fully in the hole and locked. As a fail safe the motor stops after a set amount of time if the second switch hasn’t been activated. If this happens, the ECU won’t start the next part of the closing cycle. I’ll take a pic tomorrow if you need it.

yes please to a pic nelly makes it easier to understand for me (old n senile)
 

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yes please to a pic nelly makes it easier to understand for me (old n senile)
These are the pins and hole... one either side.
 

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Discussion Starter #12
The Pins quoted by NellyTheRoc were not the ones I was original referring to, so it might be the case that i got the original issue wrong (Doah!)

There is only the one micro switch I was referring to and this is on the Passenger Side and concerns the 5th Arc.

The following picture shows the threaded bolt that is tightened by use of a star-allen key and the ball-bearing micro switch.

https://www.alfaowner.com/Forum/attachment.php?attachmentid=883947&thumb=1

The other picture is of the drivers side, where there is not micro switch and the bolt on the threaded nut that threw me!

https://www.alfaowner.com/Forum/attachment.php?attachmentid=883949&thumb=1

Hopefully this makes more sense. Again is was the tigthing of the threaded bolt on the Passenger 5th arch that solved the issue. I can confirm that the hood has been working well ever since :rotate:
 

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