Detroit Series 60 12.7 coolant level sensor bad?

Dead batteries do not voltage make.

If the problem is in coolant sensor, a shop with a computer can verify that code.

I never did appreciate them engines throwing codes on something so minor. I had a go around several times on that once.

 

If it is just the sensor: pull off the connector. The truck should start and run but you will have a check engine light on for that.
If it still doesn't run, then it's something before that.

 

For it to not run for a coolant level sensor fault, it must be set to shutdown. The next time you have it in a shop, ask them to set the coolant level to warning. That way the engine light will still come on, but it wont shut off for coolant level faults.

Also double check the wires right at the plug, they are known to break internally there. It may have just been a bad connection that you fixed, but you could have also moved the wires when cleaning it to make them touch and the problem will come back. Give each wire a good tug to make sure they're good.

 

Frozen slushy coolant throws that code too.. you have checked to condition of the coolant I assume

 

On my ol 12.7 it kept shutting down while it had full coolant for low coolant lol.. so I unplugged it and put a paper clip into the sensor plug... it's been like 6 years that truck is probably running around on medico right no with that clip in there