Ford Galaxy 1.9TDi has been suffering from an intermittent limp mode problem for several months. It can be fine for up to 250 miles and then suffer problems almost every journey - there is no pattern to when it happens at all. It can be hot, cold, on a short run, on a long run. The EML rarely comes on when limp mode occurs, if you turn off & restart it resets and can be fine for the rest of the day or play up soon afterwards but there are always at least 5 fault codes when this happens. They are ALWAYS 18346 (Aux engine coolant pump relay), 17932 (Fuel pump relay), 18027 (Glow control unit), 17849 (Valve for EGR) but we often also get 17957 (Control valve boost pressure), 17978 (Engine ECU blocked), 19561 (Motor intake manifold flap) as well.
Looking at the wiring diagram (Autodata) it shows all of these components with the exception of aux engine coolant pump run off fuse 34 which is powered up by the engine control relay (we have replaced the engine control relay and fuel pump relay as we know these fail frequently) but not all components on that circuit are throwing up fault codes.


I should also say that a couple of weeks ago the vehicle broke down completely and would not start for about 20mins. It was recovered to us and the only thing I managed to test was that there was battery voltage at fuse 34 but after that it started up and has not cut out any more (but still suffering the limp mode problem).
I have done numerous wiggle tests on all the wiring between the ECU and the fuse box and carefully examined all connections and loom for damage. We sent the ECU away to be tested at ACTronics and it passed.
I have tried scoping the EGR valve but when it goes into limp mode there are no signs of any drop outs on either the power or trigger supplies (but there was still an EGR fault code thrown up when this happened).
If you look at the pin positions for the ECU (again trusting Autodata is correct) it looks like the pins for all the affected components are in close proximity so my theory is still that there is an internal fault in the ECU (maybe on a shared circuit board?) but how do I prove this? Any other suggestions or advice are most welcome please.
Finally looking at some of the ECU repairer sites, it seems as though this model does give quite a lot of running issue problems but no more information than this and at £1100 for a new one I do not want to gamble...
Thanks in advance and sorry for the long but hopefully detailed post.