Low coolant sensor IXS

I just went through this on my Volvo Dd13. I did find a very small crack in my radiator and another in the reservoir. Replaced both. Still has the same issue. Replaced the sensor. Still had the problem . After a lot of reading I checked the DPF manifold that sent fluid through the DPF tank. There are two lines running through the DPF tank that use coolant from your radiator. That manifold was leaking like a sieve. If your getting a code telling you Bad DPF fluid you might have a pin hole leak on one of the lines running through the tank polluting the DPF fluid with coolant.
Replaced the manifold and problem was solved.

 

Unplug the sensor and with a multimeter measure the voltage, should be 4.75 to 5.25 volts, then wiggle the wiring around and see if it drops out. I usually find the wire is broken inside the insulation with in a few inches from the connector, pull the pins out of the connector and cut the wire back then put on new pins, so the problem is fixed. I have seen where you can get a new complete connector with pig tail that makes it an easy fix.

 

The coolant sensors on cummins/peterbilt are crap. Ive replaced 4 in the last 2 years. To get rid of the alarm just unplug the sensor itself. You will have a check engine light on.. If you just replaced the sensor then maybe your break could be in the wiring. Just trace it back from plug and see what you find.