Back to Forum
Post a Response
    Re: FORD TRANSIT LIMP MODE Archived Message

    Posted by Paul Gunstone on February 14, 2010, 10:50 am, in reply to "FORD TRANSIT LIMP MODE"

    Hello Eric.
    Don't take this the wrong way, but if you are working on a 3 year old diesel & are having difficulty in understanding the data you recieve from your scan tool, then really you need to take a diesel training course. Modern diesel technology has moved on so far that it is now as complex or even more complex that the petrol closed loop systems that are in use! The code which you have received is actually quite well described by the scan-tool itself. A modern common rail diesel system will run at approx 50% of the available effieciency of the system. As a leak or a worn component starts to develope, the fuel pressure regulator will start to adjust to compensate for for this, that is, until it can adjust no more, or the ECU feels there is a danger to the system, hence why the vehicle goes into a 'limp-home' situation. If the tool you are using has a 'live data' facillity for this particular system, display the data for the fuel pressure regulator's duty cycle & start the vehicle. Watch the regulators reading & it should be no more than 16 - 18% at idle. If it is above this, there is a good chance you have a system leakage. Now comes the tedious part: You now have to find the leakage! Is it excessive back leakage at the injectors? Damaged or faulty pressure reg? Weak high pressure pump? Fuel line or filter blockage? Airiated fuel supply? Faulty rail pressure sensor? Etc, Etc. Most common on this system would probably be faulty injectors, but the only real way to diagnose this system is to do a full test & elimination process, Sometimes the use of a good oscilliscope is required to see just what is going on!

    Hope I have not bored too many people with this & I may be corrected on some points I have mentioned, but I would strongly advise anyone who is intending to work on the complex diesel systems out there to get some training. Bosch, Delphi, James Dillon & Frank Massey all provide common rail diesel specific training courses and even in this current economic climate, it is money well spent & you will soon see a return on that investment!!!

    Many thanks,
    Gunner.

    Message Thread:


Copyright © uk autotalk