Truck Repair: freightliner fault code, water temp gauge, regeneration system


Question
QUESTION: I have a 2007 freightliner century with a Detroit series 60 engine. I am getting a fault code that looks like this
eng fuel temp
sht hi 128 174 03
the truck does not have an exhaust regeneration system on it.
do you know what this fault means? and how can I clear it?
I don't know if this is related,but my water temp gauge is not reading properly.the fan is coming on and off at proper times, but the gauge is not reading accurate temps. sometimes when I step on the accelarater the temp gauge goes down to 125 degrees. then pops back up,it floats around while im driving sometimes also.is the gauge bad,or is this related to the fault code?

ANSWER: if you have a a clear bowl fuel filter that sensor is in the bottom of it. nothing crucial will happen just a fault code to annoy you. doubt your water gauge is bad if anything would be the temp sensor. The way it drops to down to 125 when you step on the gas makes me wonder if the thermostat isnt stuck open is the fan running when it does that. on flat ground you should be running around 190-200 and above that on hills. Now thats on the older 60 series ive never run the road with a newer 60 series to know what they like to run at.

---------- FOLLOW-UP ----------

QUESTION: no the fan is not on when it does that.it usually runs between 190 and 200 and higher on hills like you said. but now for some reason my temp gauge reads 150 or a little lower when im driving, and will bump up to normal temp when I stop. I can tell the temp is wrong because on hills the fan will kick in when the temp goes up like normal,but the gauge will be reading 150-175 degrees. so the sensor that cuts the fan on is working properly even when the guage is wrong.could this still be the temp sensor? and where is the temp sensor located?

ANSWER: Yeah that sounds alot like a gauge is bad. You can't just change a gauge on those trucks though you have to change the whole dash cluster. Those are about $1000 bucks not sure on freightliner but believe they have to be programmed and are non returnable. The older detroits had one in the head back at the firewall on the pass. side. Not sure if the newer detroits are still in the same location. Does sound alot like the gauge but you might try the temp sensor first its alot cheaper.

---------- FOLLOW-UP ----------

QUESTION: this is what happened to me 3 times today.the check engine light came on when the fan came on.and the temp gauge went to zero. when the fan goes off the check engine light goes out, and the temp gauge went back up to 150-175.the fault code is the same as question 1. do you have any idea what this could be?

Answer
I would get it on a laptop and find out what the code is pulling up. You have something with a wire problem a sensor problem or a gauge problem. Getting the code can help lead you in the right direction and could also be tied to gether with your fan solenoid wires. If your trying to save money from a shop bill i would start by putting a temp sensor in it. and move on from there. If you google detroit diesel temp sensor location theres a picture that will show it for you located on the back passenger side of the head.