Kuga fault code U1900

[Neilparker63]

I was wondering if anybody on here could give some advice on a fault code that has come up on a diagnostic on my 2010 Ford Kuga TDCI, After receiving the Engine Malfuction warning on my dashboard instrument which comes on when the vehicle is idle and moving. The vehicle drives perfectly fine and I have not noticed any major faults. The diagnostic reading gave the code u1900 - Can Communication Bus fault - Intermittent.

[Tdci-Peter]

10 hours ago, Neilparker63 said:

The diagnostic reading gave the code u1900 - Can Communication Bus fault - Intermittent.

On its own, that can cover a huge range of faults. The CAN buses go to all major electronic modules in the car, so there seems to be an intermittent fault somewhere in one CAN bus. That is a lot of connectors, wiring loom splices and electronic units.

I recommend getting Forscan, it can probe deeper into the car's modules than any other system apart from Ford IDS, and will indicate which module the DTCs are in.

These intermittent faults usually slowly get worse until they give some real symptoms. This then make it possible to find them but you need to be prepared with the diagnostic kit to catch them before they stop the car working altogether.

Garages are usually completely useless with this sort of fault, unless the fault is present & clear, they can not fix it. Just charge you up to £100 for each diagnosis attempt.

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Forscan is a powerful Ford specific system, Cost £15.00 for the interface. Needs a computer of some sort. (COM port, USB, bluetooth or WiFi interfaces available). You will find a lot about ELM327 & Forscan on this site, which together provide a very comprehensive diagnosis & maintenance tool. James (jeebowhite) has done a nice guide: http://www.fordownersclub.com/forums/applications/core/interface/file/attachment.php?id

Forscan works best on a Windows laptop, with a USB ELM. The Tunnelrat one (below) has been reported to work well by several people. Forscan is also available for iOS & Android for some tablets & phones.

For a USB ELM327 adapter, see
http://www.spanglefish.com/TunnelratElectronics/index.asp?pageid

Wireless ELMs are also available (bluetooth & WiFi), but are often not as reliable as the wired ones. Also they are rare in the "modified" form which is needed to access the 2nd Ford bus system. This 2nd bus is the MS-CAN bus, and links all the car interior electronics like door modules, and the BCM (aka GEM). But a standard ELM will still work with all the Underbonnet Modules (PCM, ABS etc) and with the IC (Instrument Cluster).

For an bluetooth wireless ELM, which one user at least says works with Forscan, see the KW902: http://www.ebay.co.uk/itm/ELM327-KW902-Bluetooth-Scaner-OBD-Link-OBD2-Diagnose-Interface-Tester-white-UK-/281631334205

The Forscan programme is free (in Windows format) and you can get it from:
http://forscan.org/download.html

Note: Simply reading the codes can do no harm, and does not change anything. Just do not reset the codes (and you would have to ask the scanner to do this) if you are going to take the car to a garage.