W210 boot release issue

[roger574]

I wonder if anyone has come across an issue with the boot release on a W210 (specifically 1999 E55), whereby the boot release will operate, either from the key fob or from the console button, precisely ten times before failing?

After failing, the boot can still be opened via the mechanical key and, if the power to the vacuum pump beneath the rear seat is disconnected, it seems to reset itself and will then work a further ten times until it fails again.

My local MB indie has checked all the electrics to the pump and he has recently fitted a brand new vacuum pump which hasn't fixed the issue.

Anyone have any ideas please? I could understand if it randomly failed but to work for exactly ten times and then fail seems to indicate a very specific issue!

Thanks,
Roger

 

[Dec]

Is your car alarm working properly, test it over a 3 minute period, see… http://www.mbclub.co.uk/forums/electronics/169666-w202-how-test-car-alarm.html


Dec

 

[roger574]

Is your car alarm working properly, test it over a 3 minute period, see… http://www.mbclub.co.uk/forums/electronics/169666-w202-how-test-car-alarm.html


Dec

Thanks Dec - I'll check with my indie who has the car at the moment.

I know he replaced the alarm siren a couple of months ago as it was draining the battery (and fitted a new battery at the same time). The boot issue pre-dates all of this though.

 

[Dec]

That most likely rules out the alarm then, is there any possibility the indie replaced the siren with a second hand/used siren?

Is the boot being opened over a very short period of time or is this over several hours?

Dec

 

[roger574]

Hi Dec,

No, it was definitely a brand new alarm siren (well, that's what I was charged for and I trust my indie!).

The boot release seems to work over a period of about 4-5 days.

IIRC, after the new vacuum pump was fitted a couple of weeks ago, I collected the car from the garage on the Monday evening and the boot release worked perfectly until the following Sunday morning. I'd opened and closed it a few times on the Saturday so it was working then.

Roger

 

[Dec]

Any time you lock or unlock thee car, with any of the cabin switches or the remote fob, the vacuum pump should run for about 2 seconds, not easy to hear it run from outside the car.

When the car is fully unlocked, pressing the boot lock inwards will cause the vacuum pump to run, again, ideally for about 2 seconds.

If you hear the vacuum pump run for a lot more than 2 seconds… say 6 or 7 or more seconds …then there might be a leak somewhere.

Dec

 

[roger574]

Cheers Dec - I'll try that next. Thanks for all your help!

Roger

 

[roger574]

Issue now SOLVED.

According to my indie, at some point in the past some liquid had got into the CAN wiring in the front passenger footwell which had activated some kind of emergency mode which meant that the boot release would only work ten times before shutting down. Removing the power from the CDL pump reset the count back to ten, apparently.