I have an 2003 Relay 2 litre HDI. I hope someone can help as I have half the van apart trying to locate the problem and have now found this website. The problem is that the Speedo stopped working, mileage is not increasing, reverse lights not working and have an aftermarket rear proximity reversing alert, which has also stopped working. The engine auto-diagnosis warning light also remains on (I have tried to reset this but it still reamins on) I also have had a towbar fitted with relevant electrics. Have found under bonnet fuses number 11 fuse has blown when replaced just blows instantly on ingition being turned on (in owners handbook fuse no. 11 says it is ECU, but on underside of fusecover this fuse is shown as an openbook and there are 2 other ECU fuses there as well which show the normal symbol for an ECU). Have wired up a headlight bulb into number 11 fuse and with ignition on have tried to disconnect lots of things hoping this would show me the fault, but nothing has showed. I have found that by removing no. 18 ECU fuse that the bulb goes out. I am hoping it may be a speed sensor or something similar and not a broken ECU. Does anyone have any advice on this. Many thanks Chris