Renault Trafic dci 2004


Renault Trafic non runner.  Been at previous garage for 2 weeks without success.  The immobliser light was flashing normally with ignition off,  when switched on the red light would illuminate permanently without flashing,  signifying a communication error between modules.



In Renaults wisdom to gain access to the UCH the dashboard has to be removed. Once access was gained we can then check continuity between different components. With accurate wiring diagrams a diagnosis can be achieved.


In the engine bay the ECU was exposed and the wiring loom stripped so continuity could be checked, where it was found that the canbus line between the UCH and engine Ecu was open circuit.

Now it was a case of tracing the correct wiring back to the UCH to find the break.

A simple repair was made to the wiring and the van ran fine.

A very happy customer picked up his van within a couple of days and could get back to work.


1 comment

Neil Whiston said:

June 8, 2017 at 7:37 pm

No easy way really. Usually it’s the loom in the engine bay. Remove loom from ecu and strip away tape and examine. Renaults are notorious for corroded wiring

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