Megane 1.6 16 valve 2001 petrol no speedo (K4M700 engine)

[pjl1962]

Hi everyone, I an in the process of having a look at the above vehicle. It is a 2001 plate and has done 78,000 miles. Several other people have had a go at this one and gave up! As I do not like being beat, I am still scratching my head. The previous other attempts have fitted a genuine renault speedo cluster and done some basic earth checks etc.

So far I have done the following:

Checked all earths, live feeds, to both ABS computer and Injection computer and are all ok, checked the usual fuses for faults and poor or corroded connections, checked earths on chassis, engine, and gearbox for poor corroded connections and security.

Using the genuine Renault clip diagnostic tool I have checked all on board computers for faults/DTC's and there are none. If I go into the ABS computer and look at live data, all four road speed sensors are operating as they should and reporting vehicle speed.

I have looked for a vehicle speed sensor and have found on this particular model that it does not have one, it picks up its speed information from the ABS computer, which at the moment I assume is working ok with the live data I have observed.

If I go into live data on the injection computer, it cannot see road speed, this is my start of the problem. I have contacted a mate at Renault for some information, he informs me that the injection computer recieves road speed from the ABS computer as it has no physical speed sensor on the gearbox. According to him one of the wires comes from the ABS computer, then splits off two ways:
one goes to the injection computer and the other directly to the speedometer. He tells me as all Renaults suffer from this wire/s often corrode and break at various points in the loom and give this type of trouble.

He has no wiring diagram for this type of engine on this year, has anyone else got information, diagram or any idea of the colour codes as I am getting to the point as I can go no further without some data on this vehicle.

any help is very much appreciated, kind regards Paul