XPE-09-4604 Fault Code!!

Hi all

Have had this code appearing randomly over 2 days, clicking reset usually resolves it but it has got to the point where the machine just cycles up then errors again with the same fault. The fault refers to "Developer 4 (K) TC sensor temperature too high". Is this a flaky sensor that should be replaced or something else. Had an engineer out yesterday who spent all day replacing the fan at the back of the machine etc etc, I come in at 2am and 30 minutes later the fault is back!! Not happy...any help much appreciated

 

I would have the tech replace the sensor... if that is not the problem clean or replace the AC filter..we have gotten some over temp. faults due to a clogged air filter