Came to garage on a tow and non start.

Can be cranked for 2-3 seconds with no spark , no engine start.

Fuses, relays etc ECU power and grounds all good . Immobiliser light flashes normaly then stops when key is inserted and ignition turned on but the light stays on (should go off) when cranking. This does suggest an immobiliser fault.

The ECU scan showed several fault codes relating to missing +ve feeds to various sensors e.g. evap sensor but also an internal ECU error. So sent to BBA confident I had an ECU fault but came back No Fault Found.

Stuck ECU back on car and managed a start straight away !!!!. Switched off and could not restart so removed bat lead and replaced and it started again for a second time, but after this second start , no more starting and back to short crank with nothing !!! Noted that during the two starts the immobiliser light still stayed on . Very strange.

This time ECU code scan showed DF145 Multiplexed Network error. Nothing else. The UCH and Immobiliser checks show no fault codes. A Clio document on web indicates for this error I should check wiring on connector A of ECU Pins J4 and H3 back to UCH.This doc unfortunately gives no UCH pin info.

My problem is that Autodata lets me down again with no UCH info . I managed to trace track H3/green wire of the ECU back to a pin on the 2x20pin connector on the UCH , but my other pin J4/Brown wire looks like is not terminating anywhere on the UCH and I think this may be the answer to the non start as I think the immobiliser is working as far as the UCH but the check with the UCH to the ECU over this pair of wires is not happening.

Sorry for the ramble , but can anyone tell me how ECU pins H3 and J4 on Connector A/ Black connect to the UCH? Then I have a chance of rewiring what looks like a broken wire .

I suppose I could get the ECU decoded to remove the immobiliser check but I always like to solve things the right way if possible.


George