Coolant level sensor

Why?

A wiring issue would be my first suspect.

 

Tape a magnet to the sensor midway of probe, will let you know if it is a tank or wiring issue.

 

You have a wiring issue most likely, ive repaired dozens upon dozens of those circuits, no egzaggeration

 

Yeah i don't know much about newer trucks but what would the tank have to do with the sensor not working??

 

Newer Paccar (and most other brands) with plastic surge tanks use non-immersion CLS. The float is built into the tank and sometimes it sticks in the low position.

 

Take a multimeter between the 2 wire terminals(blue is signal, green is return) make sure its a solid connection and dont damage female terminals. You will read 4.7v approx between them if circuit has integrity, and your watching for voltage drop out as you carefully and gently wiggle harness all the way down harness, the wiring frays in insulation under zipties/brackets and even a splice on return side. A quick lintermitt loss of circuit integrity can cause low coolant light but no CE will set, throws guys off

 

Just a suggestion because easliy 90% or more of the time i found it to be wiring over the last 4 years on PB and KW, but of course like Spsauerland said it could be float/sensor

 

This quote is also directly from Cummins trainer " there is a threshold (between 5-30 seconds) with setting sensor code. If problem(fault) happens and lasts more than 5 seconds but less than 30 seconds, it may throw a CE light but not throw a code" end quote. And in the coolant level sensor the light and ding, ding annoying chime drives drivers crazy