had yellow light come on dash (engine warning) found out it is fuel temp sensor. is it important to replace asap ? what affect will it have if not replaced. hope to finish my loads for the week. so far I have not noticed any difference in engine performance. also can I just replace myself or does it need to have anything reprogrammed into the ecm? called freightliner dealer. can order part & have in a day.

This is on ser 60 det

It may affect fuel mileage. Check for a 2-wire sensor at the fuel filter header. Key switch off, you just thread it out and thread new one back in; if it was the problem, the light should go out when you key back on. Engine may start hard after if you lose too much fuel ( have the new one ready to plug the hole ).

got the new sensor. dealer had in stock. location of sensor is on back of fuel pump. will change today. sat. I dont have the typical fule filters, so I am not sure about any fuel filter header. I have the davco sys.
thanks for the reply.

That was one of the easiest fixes. 3/4 wrench. dripped about a tbls of diesel out & then stopped, screwed new sensor in.