So we have a small fleet of 2005 FE-300 with the DT-466EGR and have had issues with the coolant temp gauges since day 1. It appears that the gauges in the instrument cluster only go to 210 degrees. We have had many buses loose hoses/coolant and drain the entire system and the temp gauges stop at 210. After runnings several buses till the engine temp reaches 220 (verifying with IC softwear) the gauge still reaches 210 only. Now as far as I have been able to figure out is the ECT sensor feeds the ECM and it sends a signal to the Black box (forgot what it is called) in front of drivers left foot and then feeds the gauge cluster. Any one had issues with this on there 05 buses and anyone have a fix for this? This is in a FE bus and is not mulitplexed and it is not the same set up as an BE or CE...
During my time working on this issue I finally found the problem as to why our low coolant sensors have never worked. Seems someone at IC programed the coolant sensor as a Float type sensor in a plastic tank. So I have been re programming the buses with the conductive probe with metal/plastic tank. Then I have to reset the engine warning/shutdown feature to 3 way (RPM, EOP, ECT and ECL). At least we now know when a bus is low on coolant.
All our FE buses came with them but the ECM was programed for a plastic surge tank with float sensor. Also the EWPS was set to 2 way and needs to be programed to 3 way for the ECL to actually work regardless of the type sensor and tank. All or FE buses have metal tanks and conductive sensors. So basicall they never worked. I have been going around and re-programing the ECM to the correct Surge tank / sensor and changine the engine warning to 3 way. Lost an EGR cooler last week due to a boost pump leaking and the driver did not know it was out of coolant and the temp gauge only going to 210deg. Our RE buses do not have sensors at all in them and we are looking into putting them in at some point. Need to find all the needed wiring and which terminal in which connector in the ECM to install.