I assume from the "sensor light coming on" you mean the engine managemnet light and if this the case you will have to get the engine management system read by computer and as the Renault Traffic, Vauxhall Vivaro both share the same electrical system as the Nissan van it will be a main dealer that you will need I have been there with these vans you can not get into the computer system even the AA and RAC have problems.
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