Hi all i have fitted the genuine ford towing harness (module, trailer prep wiring and the towing plug).

I have connected it all up and nothing seems to work there is live power going to the module and its all earthed correctly. I borrowed my dads lighting board and nothing seems to happen, i did not know if you need to get ford to do something with the ecu to allow the module or anything.

Any ideas ?? 

Also on another point about the wiring, i had to fit the trailer prep cabling myself and on the instructions its showing a left hand drive car and the plug you splice into behind the glove box on the right hand-side of the car, im guessing on a right hand drive car the plug would be on the left hand-side of the car behind the gloves box??.

Thanks Daniel

1 hour ago, Almostboss said:

nothing seems to happen, i did not know if you need to get ford to do something with the ecu to allow the module or anything.

The trailer module is on the MS-CAN bus, I do not know for sure if the BCM will recognise this module automatically and enable it, or it it has to be enabled by a diagnostic system.

But I would start by checking that the CAN bus connections get through to the module (I think you have checked power and earth to it). With the ignition off (test a few minutes after turning it off), a CAN bus will read 60 ohms on a multimeter from line to line. They all have terminating resistors at both ends, so this is well defined. Pins 1 & 2 on the module connector should be the CAN bus, as far as I can see.

Pin 3 on the module should be a brake light signal.

Then I would use Forscan, a Ford specific diagnostic system capable of finding and reading all modules in the car, to see if it could detect the trailer module. And maybe even show any error codes, or even do an initialisation or reset.

Regarding the LHD plug, the BCM (Body Control Module), which handles all lighting and related matters, is always on the passenger side, and I guess this is where the plug goes. On the Focus the BCM is built into the passenger Fusebox, and I guess the C-Max is the same as they are closely related. It is the BCM that will handle trailer functions, and if any enabling has to be done, it is likely to be here.

There is also a programme called Focccus, which uses the same ELM327 adapter as Forscan, that is specifically made for turning on & off optional facilities. If you Google it, it may take you to James Simpson's site, which has some useful info, and there is some scattered around this site. But I don't recall anything specific to trailer modules.

 

 

36 minutes ago, Tdci-Peter said:

The trailer module is on the MS-CAN bus, I do not know for sure if the BCM will recognise this module automatically and enable it, or it it has to be enabled by a diagnostic system.

But I would start by checking that the CAN bus connections get through to the module (I think you have checked power and earth to it). With the ignition off (test a few minutes after turning it off), a CAN bus will read 60 ohms on a multimeter from line to line. They all have terminating resistors at both ends, so this is well defined. Pins 1 & 2 on the module connector should be the CAN bus, as far as I can see.

Pin 3 on the module should be a brake light signal.

Then I would use Forscan, a Ford specific diagnostic system capable of finding and reading all modules in the car, to see if it could detect the trailer module. And maybe even show any error codes, or even do an initialisation or reset.

Regarding the LHD plug, the BCM (Body Control Module), which handles all lighting and related matters, is always on the passenger side, and I guess this is where the plug goes. On the Focus the BCM is built into the passenger Fusebox, and I guess the C-Max is the same as they are closely related. It is the BCM that will handle trailer functions, and if any enabling has to be done, it is likely to be here.

There is also a programme called Focccus, which uses the same ELM327 adapter as Forscan, that is specifically made for turning on & off optional facilities. If you Google it, it may take you to James Simpson's site, which has some useful info, and there is some scattered around this site. But I don't recall anything specific to trailer modules.

 

 

Thanks for the reply i will be having another look at the car tomorrow, module is differently getting its 12v supply and has a good earth connection. I will look at reading the lines tomorrow and see if they are correct. As for the Fusebox being part of the module ie connecting to it in some way, when i looked at the instruction i got, it says to plug in a 40amp block fuse into one of the slots but you cant as there is no pins for it to slide on to. i assumed after i had connected the CANbus Wire behind the glove box (pin17 and 18 i think) and connected  pin8 at the rear too the 3rd pin on the green connector, 4th being the earth and gave the module its 1v supply it would work.

For the Forscan and doing it yourself is it something relatively simple to do or is it worth taking into ford to get them too look into as i know i will need to change parameters. IE when the car is in reverse with a trailer it will not use the park sensors and not use the revers light on the car.
 

Once again thanks for your help.    

 

Daniel

 

2 hours ago, Almostboss said:

For the Forscan and doing it yourself is it something relatively simple to do

Getting Forscan is worthwhile for just about every Ford owner. It may still be necessary to take the car to a garage for work to be done, but being able to do initial tests yourself is very useful, and can save money. That applies to this trailer problem, but also to many other engine or electrical problems that all too often arise.

For a bit more about what it is and how to get it, see:

Talking about the wiring, do the connectors in the pic below look anything like the ones on your trailer module? They are from the Mk3 Focus wiring diagram. If they match, it could help identify if there is a wiring problem, as the wiring info in that diagram is also then likely to be relevant. The instructions with the kit sound very dodgy to me!

C12 Pins 17 & 18 seem to be the MS-CAN bus. C12 is a big 40pin connector somewhere near the BCM.

yeah the digrams look the same the one on the left being the 12v line and the one on the right been the green ms canbus, the green connector on my car is only a 4 pin rather then the 5pin showed.

 

below are parts of the instructions showing connecting the wire into the MS-canbus near the bcm. I was wrong the pins are 18+19 of the top of my head i thought they were 17+18.

 

Picture 4 showing the BCM behind the 40pin connector and then picture 3 showing to plug the 40amp fuse into the block but when i looked this morning there are no connectors for it too go onto its just empty.

I also ordered a modified elm327 that should arrive toady. fingers crossed.

The trailer tow module needs switching on via the central car config in the bcm before it will work. 

If you have the green connector in car there is no need to splice in to the canbus. Post up a photo of the green connector.

4 hours ago, Almostboss said:

I also ordered a modified elm327 that should arrive toady. fingers crossed.

Ian has confirmed that the BCM needs to be told to enable the module. It is possible that Focccus can do this, though I think development of that software stopped a few years ago. However this should be a very basic option, so may work. Towbar is listed as #76 on the James Simpson site:

https://www.jamessimpson.co.uk/focccus-central-ecu-config-edit-elm327/

One warning: Don't experiment too freely with all the options. I have heard reports of people enabling options that are not available in their car physically, and then getting errors and being unable to disable them again! But if the option is going to a Ford dealer, who will probably charge almost as much as fitting the thing, just to enable it, then it is worth a try.

Also worth double checking the CAN bus is at the module and the right way round. All the wiring details you have shown stack up with the Focus wiring diagram, which is available on this site, all 130 odd pages of it!

In the diagram, the fuse F26 is marked as being either fitted into the rear fusebox, or a stand-alone inline fuse.

As Ian suggests, I am a bit surprised the module connector was not already there, but Ford do love to save the odd penny or so by missing out bits if they can.

 

3 hours ago, iantt said:

If you have the green connector in car there is no need to splice in to the canbus. Post up a photo of the green connector.

It did not have the green connectors before i put it in.  Thanks iantt

 

2 hours ago, Tdci-Peter said:

Ian has confirmed that the BCM needs to be told to enable the module. It is possible that Focccus can do this, though I think development of that software stopped a few years ago. However this should be a very basic option, so may work. Towbar is listed as #76 on the James Simpson site:

https://www.jamessimpson.co.uk/focccus-central-ecu-config-edit-elm327/

One warning: Don't experiment too freely with all the options. I have heard reports of people enabling options that are not available in their car physically, and then getting errors and being unable to disable them again! But if the option is going to a Ford dealer, who will probably charge almost as much as fitting the thing, just to enable it, then it is worth a try.

Also worth double checking the CAN bus is at the module and the right way round. All the wiring details you have shown stack up with the Focus wiring diagram, which is available on this site, all 130 odd pages of it!

In the diagram, the fuse F26 is marked as being either fitted into the rear fusebox, or a stand-alone inline fuse.

As Ian suggests, I am a bit surprised the module connector was not already there, but Ford do love to save the odd penny or so by missing out bits if they can.

 

i have been looking before with the elm327 and i got onto forscan and found the trm module so the car can see its there.  just need to get the elm software working to see if i can activate it.

IT WORKS !!! I activated it in focccus and it's works.

Thanks you both for your help it's been much appreciated.

 

Daniel 

Hi Daniel

Sorry to jump your thread, but I’m in the process of fitting a towbar etc to my focus. All the wiring looks pretty simple but it’s just the bit at the front of the car I’m a bit unsure of (section 18 and 19 shown on your pics).

Iv taken the glove box out and found the connector I need up behind it. The new wire that comes with the kit has four parts, am I right in saying two go in pin 17 and then two in pin 18? Section 19 left me a bit confused.

Also how easy did you find doing the bcm update yourself?

Thanks 

1 hour ago, hineyho87 said:

All the wiring looks pretty simple but it’s just the bit at the front of the car I’m a bit unsure of (section 18 and 19 shown on your pics).

I find those drawings really difficult to follow too! What idiots come up with this stuff.

But I would guess it means you should cut the existing wires to pins 17 & 18, and wire the new ones up so one new twisted pair (Vt/Og & Gy/Og) goes to the shortish cut wires to the plug, and the other new twisted pair goes to the cut wires to the harness.

I suspect if you test the new wires (A1), there will be a dead short between both Vt/Og wires, and also between both Gy/Og wires.

To be technical, the thinking behind this is electromagnetic. These busses carry moderately high speed signals, and they are intended to be one pair of twisted wires from one end (BCM) to the other end (Instrument Cluster). All the intermediate bus stops (where information gets on & off the bus), should be short spurs to avoid nasty echos. So to wire the CAN bus to the trailer module, it is taken back to the module as a pair, spurred off into the trailer module, then brought back to the BCM as another pair. Hence the 4 wire connection, when by simpler (Non-electromagnetic!)  logic it could be just the two.

Thanks for the reply peter.

That makes sense now. If only ford put a bit of wording alongside the pictures. Am I right in saying it does matter which pair of wires go to the connector end or the wire side? 

For the bcm update, ford have said about £55. Does that sound about right? I’m going call a few garages but given what you need to do under the diy option it seems easiest money they will ever make

Edit - Above should say it “doesn’t” matter which pair of wires go where

4 hours ago, hineyho87 said:

If only ford put a bit of wording alongside the pictures. Am I right in saying it doesn't matter which pair of wires go to the connector end or the wire side? 

For the bcm update, ford have said about £55. Does that sound about right? I’m going call a few garages but given what you need to do under the diy option it seems easiest money they will ever make 

Both pairs are identical, as far as I can see, so either can be used. As long as they stay in their pairs! Muddling up the wires from the pairs would be like an Indian Motorway, where traffic seems to travel in both directions on both sides of the dual carriageway!

Ford dealers like easy money. Ford Corporation assists them by hiding all useful information as much as possible, trying to force everyone to use franchised dealers, who in turn are supposed to sell more Ford cars. People like the Forscan team are doing a wonderful job in trying to breach this nasty monopoly, but it is an uphill struggle.

I agree about words being much better than funny little icons of eyeballs etc. They are probably trying to avoid costs of translations, but French and English would, I suspect, cover at least 80% of the people who would be reading this information.

Tell me about. Thanks for your help. I managed to fit the electrics today.

Just to sort the update now. Goin call round a few dealers for price to see if it’s worth me doing it myself or not.