VM Transit CAN bus to ABS and BCM coms problem

[johnpietila]

I have 2010 VM Transit 2.4 L turbo diesel with 245 k. I has developed
1 UO 121 and UO 140 fault codes indicating loss of ABS and BCM coms
2 resulting in loss of
2a ABS
2b ESP
2c hill assist
2d indication when to change to next gear
3 as well as occasionally the engine runs up to a minute or more after turned off
4 brakes lock at slow speed as if the hill assist was still on
5 have not found anyone on Brisbane willing to diagnose the problem EXCEPT
6 speed sensors at each wheel proven to read consistent equal signal when driving
7 Auxiliary (second) battery replaced while still showing normal life
It looks like I will have to investigate the problem further. I am aware of basic tests such as
8 determine 120 ohm termination resistors are connected, all earths and 12 v supplies are OK

At present I do not even know how many modules are on this CAN bus. Where can I get circuit diagrams?
I have a genuine Ford maintenance manual download from EManualOnline but this does not seem to cover much along the subject, referring to the Ford WDS system, presumably the dealer accessible device.
Dealers also rather proud of the fact that they do not have staff trained with vehicles over 10 years old!

ANY SUGGESTIONS, I AM DETERMINED NOT TO GIVE UP. What test gear would be useful?

[trnx]

2a ABS
2b ESP
2c hill assist
2d indication when to change to next gear

The above are linked.
ABS releases a brake. ESP applies a brake. Hill assist braking is released as the clutch pedal is raised. Indication to change gear likely uses the ABS which give the vehicle speed on the E5 vehicles - the 2010 E4 may have a speedo drive from the gearbox.

Engine running on - electrical/fuel - a slow to react solenoid fuel shut off valve could cause running on. On some circuitry an to earth switch is used the power is earthed rather than power to switch to break the supply.

determine 120 ohm termination resistors are connected, all earths and 12 v supplies are OK - green crusties at a connector could give a false reading.

The running on of the engine could be a poor starter switch - cheap and easy to replace.

Diagnosdan, Pine hollow diagnostics, RMS diagnostics has vid on a transit van, South Maine Autos, Diagnosticdan, Eric the car guy, ORiley DPF mostly DPF but he comes across odd problems.

The van is 15 yr old - green crusties are likely at the electrical/onic connectors. Itermitent operation, reduced flow, reduced V, division of V, high to slightly higher resistance.
Likely there is the 12 V system and the 5 V system. The DMM puts out 6V which can disturb electronics.

[Altransit]

I've had similar on two different Ford cars, and a Volvo, and it was a wheel sensor every time. If not the case with yours, what about the rings that the sensor reads, on the wheel
Clutch and brake pedal switches can create some interesting faults too

[johnpietila]

Thanks so much, finally a glimmer of HOPE!

1 What test gear do you suggest? How can I find the individual CAN Bus units locations? No help from Ford head office so far.

2 hesitant to prize open unnessarily many plugs to best verify the connection of the 120 ohm end of line resistors with past experience 'to leave sleeping dogs lie'. Horrified to see COMS signal using standard quality plug pinout, I am used to separate quality plugs on other coms systems such as Profibus, HDMI etc systems. Have seen videos with using a 'breakout box' for OBD scanner socket to read the 120 ohm end of line values, OK if correct but this would not show where the fault is if not OK.

3 Tried to check clutch and brake switch contacts but pins so close together making impossible to use DVM, was able to by new brake switch but not the clutch one.

4 would like to understand CAN bus principles, where would be a website? Have spent all my working life (now 88) on industrial automation but never with CAN bus. It should not be 'rocket science'.
?
5 Any chance to call you on Whats AP ?

Forever grateful
John Pietila
Brisbane Australia

[metalworker0]

A youtuber called Diagnose Dan usually discusses a lot about can bus, how it works, what to check, he goes into a lot of detail. he is one of those garages, where other garages send their unsolvable cars, when they give up on a fault.

https://www.youtube.com/@Diagnosedan/videos


all the best.mark

[trnx]

Forscan is the one most use. DTCs and Live Data + +. You'll need to know how to use Forscan.
Your van is an E4 mine is an E5 what is the same or different - so far only Ford know, those who know about electronics and have the Ford info'.

Takes a lot of looking the names given (youtube contributors) have a good presentation. RMS uses All data has a big screen shows what's what, what goes where.

At 88 yrs it's a lot to take in. Consider the method of applying electronics to be illogical. Open your mind to what's new - it's the way it is. You'll be well stuck in the grove by applying old school thinking.
It is not a two way road or a one way road - but it can be - it can also be multidirection.
Binary hexidecimal a code is very quickly transmitted and received.

There is info' on the web.

The video makers are helpful types.

The power supply, the fuse, the switch, the electric user unit, the return to earth/neg.

Now there's an electronic unit(s) in the system(s). The switch can be on the return side. There'l be monitors/sensors on/in the system.

Capacitors are no longer a barrel on a PCB they are little flat insect like things.

I doubt if I could help you you've likely had more exposure to controls than I have.

What test gear do you suggest? Watch all of the vids you can esp RMS and Pine hollow diagnostics.

[johnpietila]

Thanks for good hints on where to go.
John

[trnx]

Look for info' re' motorcraft - if in the UK don't tick UK tick USA for country to get access to the motorcraft site from where at a fee one is supposed to be able to look at Ford info' re' your vehicle.
You may need to record what you do to access and then record the wiring diags etc. A recording of your screen won't let you use a linked web page - as is with a pdf.

Motorcraft: There's info' on this forum and on the internet re getting access.
I think it was about £15 per hour to view. However to use the available info' one would need to have it - so as to use the info' as a pdf.

A usable CD or pdf of the whole info' (workshop manual) re' your vehicle is better.

So if one knew what the problem was and needed to confirm it - then one could possibly download that page of info' from motorcraft.

Never done it so don''t really know - to much of a get it free type - like the sleeping dog - wait until it needs to be done when money is involved esp as what is to my mind an extra. I've already bought the bloody van so why should I pay for info' about it?

There's a lot of stuff on the internet which claims to have the info' for your vehicle - usually it doesn't.

DMM 6 V output - van electronics is on 5V. The wiring diags are a must have.

Your van is 2010 it is in the group Mk7. 2006 to 2011 E4. 2011 to 2014 E5. So the Mk 7s are in a group 2006 to 2014 however they are not all the same.

[trnx]

https://www.youtube.com/watch?v=AlDnCNjF88M

Gives an insight as to what it's about.
Good to see that which is available to fault find.
Good to see the big screen with the electrics on it.

[johnpietila]

For 2010 VM series 2.4 turbo diesel, where ON EARTH can i get hold of At least a diagram of all the computer modules on this CAN bus?

[trnx]

Forscan lists the modules that are on the van.

[knobby1]

For 2010 VM series 2.4 turbo diesel, where ON EARTH can i get hold of At least a diagram of all the computer modules on this CAN bus?

BEMM has a diagram of all modules etc...Just download it as a PDF onto your PC and you'll have it forever.

https://www.scribd.com/document/5091554 ... V-347-BEMM

Lord Knobrot (Smithy)