Scan tool indicates no voltage on Lambda Sensors
156 2.0 JTS (2003) I have recently experienced a 'Motor Control System Failure'. This time, I have been advised by a dealer, the fault code indicates cat efficiency out of limits or low. This however, apparently can be down poor Lambda sensor connections or the CAT. i.e. the pre and post CAT figures do not match. Anyway to save some money on the basis that it may not be the CAT, I purchaded an elm 327. Next time the fault came up I managed to also determine the same i.e. CAT efficiency. I was also able to interogate the sensor readings which shows only one lambda (out of four) giving a voltage. This clearly isnt' correct as they should all be giving around 400mv I believe.
Does anyone have any thoughts. Suggestion would be that the Lambda's are not working however surely this would throw up a Lambda fault code. Also the two pre cat sensors (5 wire, wide band - very expensive) have been replaced about 5000 miles ago.
Any help would be great.