Lexia Tow bar Trailer Presence Missing

[manuk]

Hi All,
 
Wonder if the community who has experience of using lexia shed some light and advise me please
 
I have installed the Citroen B9 specific wiring harness, and when attempting to activate the trailer (via lexia accessory menu suboption) the module is recognised however lexia reports “trailer presence” missing, even though the trailer is plugged in. Resulting that none of the lights is working on the trailer
 
Any guidance much appreciated in advance

[RadgieGadgie]

If you have done the 40A fuse under the bonnet fuse box, have you got power coming out the trailer socket?

[RadgieGadgie]

My problem all along was the factory installed front to rear loom, I even went to the length of buying a new box from Citroen France (cheaper) it came with a loom included, put the new box on and still did not work.
A lot of frustration ensued until as a last resort temporarily plugged in the new loom (front to rear) that came with the box from France and it solved all issues.
So now i have the dud factory fitted loom (UN-connected) but still in situ with the new France loom tucked away sitting along side it in replacement and working.

[manuk]

My problem all along was the factory installed front to rear loom, I even went to the length of buying a new box from Citroen France (cheaper) it came with a loom included, put the new box on and still did not work.
A lot of frustration ensued until as a last resort temporarily plugged in the new loom (front to rear) that came with the box from France and it solved all issues.
So now i have the dud factory fitted loom (UN-connected) but still in situ with the new France loom tucked away sitting along side it in replacement and working.

Hi

Thank you for your quick response and contribution

Re Maxi Fuse (40A) yes fuse has been installed and 12V supply is present on the white cable

Re cable loom that is very interesting to read, looks like need to find a way to hook up the second loom....

My experience is as follows

1: trailer unit activation successfully activated (though I am suspicious that this is truly activated)
2: trailer module recognised by lexia
3: lexia reports "trailer presence" MISSING

By way of helping to me understand when you plugged in lexia what issue/error did your lexia session report

Regards

[manuk]

My problem all along was the factory installed front to rear loom, I even went to the length of buying a new box from Citroen France (cheaper) it came with a loom included, put the new box on and still did not work.
A lot of frustration ensued until as a last resort temporarily plugged in the new loom (front to rear) that came with the box from France and it solved all issues.
So now i have the dud factory fitted loom (UN-connected) but still in situ with the new France loom tucked away sitting along side it in replacement and working.

Hi

Thank you for your quick response and contribution

Re Maxi Fuse (40A) yes fuse has been installed and 12V supply is present on the white cable

Re cable loom that is very interesting to read, looks like need to find a way to hook up the second loom....

My experience is as follows

1: trailer unit activation successfully activated (though I am suspicious that this is truly activated)
2: trailer module recognised by lexia
3: lexia reports "trailer presence" MISSING

By way of helping to me understand when you plugged in lexia what issue/error did your lexia session report

Regards

Temporarily hooked up the back to front harness and the effect was same, leading me to think could this be the BTC module itself that is faulty
 
My question to all forum members who have activated the trailer using their own lexia instance or who have the original tow bar wiring in their cars
 
When checking the identification option under fault finding in lexia does it return the information (please see attached)
 
Reason for asking this question is that in my setup when I check for Identification of the unit it will not return the information as per images supplied

[ntm1275]

I have done the fitting and activation on my Lingo and all went OK

1. Fitted 40amp Maxi fuse (this gave power to the thick white lead)

2. Check all plugs are fitted to the fuse box underneath the glove box (on some models not all of the plugs are 'plugged in' to the fuse box at the factory - there should be 3 plugs - one large plug with a single thick white cable, another smaller plug with a single thin cable, and then a third with small plug and 4 thin cables)
The one that isn't always plugged in is the one with the 4 thin wires.
All three MUST be plugged in

Here is the socket and plug that needs to be attached
         

3. In the rear of the car, there should be 3 plugs (one large red plug with a single thick white cable, an orange plug with 6 thin cables and a green plug with one thin cable)

4. Fit the trailer fusebox and connect the three plugs mentioned in point 3

5. Connect the additional loom that goes to the trailer socket (If you bought the 7pin loom, then after this is plugged in to the trailer fuse box, you will be left with a spare socket. This spare socket is for the additional cables for a 7+7 loom or a 13pin loom)

6. Wire up the additional loom in point 5 to the trailer socket(s)

5. Activate it all with a Lexia/Diagbox.

When I get home today from work, I'll plug my Lexia in and take a look for you at the settings

[manuk]

I have done the fitting and activation on my Lingo and all went OK

1. Fitted 40amp Maxi fuse (this gave power to the thick white lead)

2. Check all plugs are fitted to the fuse box underneath the glove box (on some models not all of the plugs are 'plugged in' to the fuse box at the factory - there should be 3 plugs - one large plug with a single thick white cable, another smaller plug with a single thin cable, and then a third with small plug and 4 thin cables)
The one that isn't always plugged in is the one with the 4 thin wires.
All three MUST be plugged in

Here is the socket and plug that needs to be attached
 

3. In the rear of the car, there should be 3 plugs (one large red plug with a single thick white cable, an orange plug with 6 thin cables and a green plug with one thin cable)

4. Fit the trailer fusebox and connect the three plugs mentioned in point 3

5. Connect the additional loom that goes to the trailer socket (If you bought the 7pin loom, then after this is plugged in to the trailer fuse box, you will be left with a spare socket. This spare socket is for the additional cables for a 7+7 loom or a 13pin loom)

6. Wire up the additional loom in point 5 to the trailer socket(s)

5. Activate it all with a Lexia/Diagbox.

When I get home today from work, I'll plug my Lexia in and take a look for you at the settings

NTM1275

You are a SUPER STAR,

The issue was the multi-plug and the photo you supplied was exactly what was needed

I love the car but like everyone has commented before unless you know what you are looking for you will not find it. The small (4 wire) multi-plug was indeed not connected. However, although I knew about this plug already but the wonderful (NOT) documentation is what threw me as according to the documentation this plug is for the parking sensors and given mine does not have parking sensors after looking for the corresponding socket and not finding it assumed was redundant .....
 
I really believe that your post should be made to a stickie but not sure how to go about it. Though it should be updated to include the removal of yet another ingenuous design for unclipping the fuse board to insert the maxi fuse (there is a very good post and photos already in the forum)
 
Also would be great if you post the output of the lexia next time you hook up the PC to compare yours to what I am getting
 
Can I also thank everyone else who contributed to the issue whilst I was wallowing in my misery…….
 
The existence of this forum and the contributors is what drove me to buy another one, lovely cars compared to old M59 but what a pig to get to work on given its design quirks

[ntm1275]

Glad you got it sorted

I went through the issues myself and having to deal with the very poor documentation

It took me days to realise that the plug was not connected

I have been meaning to do a guide, as I took photos of the process.
When I get a couple of hours spare, I'll have a go