Catalytic Converter Temperature Monitoring

Some vehicles are equipped with an exhaust temperature sensor at the catalyst for cylinder banks No. 5-8. The sensor is a PTC resistor which allows the MS S52 to monitor the catalyst temperature. This input is considered for mixture control by the MS S52 for catalyst efficiency. In the event of an overheat situation, the PCM will illuminate the Malfunction Indicator Light (MIL) and set a fault code. Under certain load conditions, the fuel mixture is enriched to aid in cooling down the catalytic converters.