High emissions

Q My vehicle is a 1997 Renault Trafic 2.2 petrol with a Renex system, ECU 7700300496 J7T, which has high emissions. The throttle body is working poorly (no load/full load) and the sensor (ref Colvern 17-546-2699 and 9610ES133) has a switch on the back that doesn’t seem to return properly on its own, hence the high emissions; when pushed back by hand, it is OK.

We were told that a sensor and throttle body for the Trafic could no longer be supplied, so we got a throttle body and sensor from a Renault Espace which has a Bosch sensor (ref 0280120301). When the ‘new’ one is fitted, the van runs perfectly and is well within emissions range, but the service light and injection warning lights appear on the dash. On looking at the live data, it is reading 2.5 volts, but doesn’t read the sensor.

On putting back the old sensor and throttle body, the codes can be cleared and the lights on dash go off, but poor tickover returns. I am reading the codes with an ARC4 Renault V3 pod and getting ‘18 Throttle Pod circuit fault’ and the live data reads 0.05 volts.

Can a new sensor be sourced or could the old one be repaired? Should the Espace one work? Are there people out there who can fix this sort of thing? Mark Bannister

A First, I am assuming that the Espace from which you sourced the throttle body has the same 2.2 J7T engine. Although I can find no definitive evidence, the throttle body should be the same.

A simple test of the sensor can be carried out using an ohmmeter. First, unplug the sensor and place one of the test probes on the centre and another probe on one of the outside contacts. With the sensor in the fully closed position, the contacts should be either closed circuit or open circuit. Leaving one probe on the centre terminal and then swapping the other probe to the opposite outer terminal should see the opposite result (ie, if the left-hand terminal was open circuit, then the right-hand terminal should be closed circuit). By moving the sensor to the fully open position, the results should reverse, so that the connections that gave an open circuit will now give a closed circuit. Finally, placing the sensor in the centre position should give open circuit results from both sides.

The company www.actronics.eu does carry out repairs to throttle bodies, including the replacement of the sensor with an improved unit. It may be worth contacting them to see if they can help with your unit.

Also, owners’ clubs are a good source of info with regards to sourcing parts. The only Renault Trafic club I can find is

www.rtmr.org. If any parts are available, they should be able to help you find them.