Year of Manufacture *: 2004
Engine Size and Code *: 1.6 TDCi 110ps DV6
( Optional ) Scanner Used: IDS
( Optional) Fault Codes: No Coms
VIN: WF0MXXGCDM4B80198
FORD FOCUS C-MAX 1.6TDCi 110ps DV6
Alright boys and girls
I have been passed a challenge and unfortunately it involves CAN Bus technology which is something i am not very clued up on, so i'm hoping somebody will be kind enough to offer assistance? pretty please!
Ok so this has done the rounds of other garages including dealerships before coming to me and the story goes like this:
Vehicle started as an intermittent cutting out/non-start; went into ford who diagnosed a faulty wiring loom at a cost of £3000!! The customer understandably said thank you but no thank you! The vehicle has now turned into a permanent non-start. He then went online and spoke to a ford tech on a forum who told him it would definitely be a faulty instrument cluster as he's done loads of them!! £500 later the customer owns a brand new genuine cluster and takes it to ford to have it fitted/coded; Ford say they cant do it as their computer will no longer communicate with the car! He then rings James Eardley who put him on to me as we have IDS! (Hi James! )
So my story goes thusly:
Plugged IDS in and it wont communicate with any control unit, just displays "cannot communicate with PCM" and asks me to input the part number etc from the PCM. Checked power and grounds to PCM and all are good! Have scoped CAN at DLC and got the following waveform:
Now even with my limited knowledge I can tell this is bad as the high and low are meant to mirror each other.
If I'm correct the first thing i should do is disconnect the different ECUs on the network and watch for the signal to correct. If i disconnect the PCM or ABS modulator whilst scoping the DLC there is no change to the waveform, if i disconnect the instrument cluster then both lines go dead. I would imagine that this is because the cluster has one of those terminator resistor things in it?? I tried the new cluster on the vehicle (uncoded obviously) and this did not change my corrupted CAN Hi!
I scoped the CAN at the PCM Both with the PCM connected and disconnected and got the following waveforms
Im not sure if i've got wiring diagram issues (autodata) as the CAN Low appears to be some sort of power supply and considering the DLC shows no CAN Low issues... this is coupled with the fact that i wanted to scope the CAN at the ABS but my diagram didn't match up to the multi plug on the vehicle!!
Hopefully that lot makes sense as CAN Bus is something i'm a bit nervous about, if anybody could provide me with some advice and guidance it will be greatly appreciated and also an accurate wiring diagram perhaps??
Hopefully i can learn something from this job!?!
Thanks
Craig
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