C5 Mkiii X7 - Motorised Boot Not Working

[4rchibald]

When I got the car, operation of the motorised boot was intermittent. It worked for some time after a reset of the BSI and stopped working all together after few months. 

DIagBox does not see any communication with the boot ECU, which as I assume correctly is attached to the motor lift unit. 

Having a wiring diagram I decided to check cables, but I think there is a problem with the diagram. 

Could I please therefore ask someone to check wiring diagram for the motorised boot and check connection between grey plug (16V GR - pin 2) and boot ECU (pin 15), as those seems to be incorrect. 

Any other suggestions would also be appreciated. 

I suspect it's not the ECO mode as the boot does not connect nor operate in any conditions now. 

ORGA: 11440
ORT: CJ
Estate
ABS / asr - yes
Engine 2.2 HDI

 

[paul.h]

I would check the wiring between the body and boot. In the estate/tourer (and other model hatchbacks) it often breaks in the rubber tube between the 2 so is a possibility.

 

Also check the battery voltage in case it is low.

[4rchibald]

Wiring is not externally damages in that area, but this is why I'm trying to check cable continuity. 

Battery is 6 months old, but it's too big for what Citroen is specifying, but it would not explain why Diagbox does not see the boot ECU.

[paul.h]

We had this post on a tailgate not opening due to low battery voltage which made me think of checking it http://www.citroen-owners-club.co.uk/citroen/topic/21222-is-it-easy-to-change-the-battery-in-c5-tourer/

[4rchibald]

Main difference is that the tailgate would work with engine running, whereas mine is dead.