Renault Clio 1993 1.2, E7FD704, Delco SPi - MOT Emission failure - fault code for lambda sensorArchived Message
Posted by Peter Rainsley on March 31, 2005, 8:52 pm
Trade customer, car failed mot on emissions. DTC read on ACR4 as 26-lambda sensor. Datastream has lambda output locked at 438mv, i.e.the ecu is in default mode. However, actual reading at ecu is 800mv, i.e. sensor is seeing the rich mixture, but the ecu is not responding. I have checked ecu feeds and earths and continuity back to the circuit board. I have fed a varying 0-1v signal into the ecu and I still get the same lack of response. I therefore diagnosed a faulty ecu. A replacement, not new, ecu is doing exactly the same. I cannot believe two ecu's have the same fault, but there is a flaw in my diagnosis somewhere. Can some one out there enlighten me? TIA, Peter Rainsley