grantbp

I have an error i am struggling to resolve.
Coolant temperature sensor upstream of low temperature EGR cooler- error is triggered when a difference between the coolant sensor and egr low temperature sensor is seen.
- replaced egr coolant temp sensor x 2, replaced main coolant temp. Removed EGR temp sensor with cable attached in placed in cup of hot water...temp shot up to 70 degrees C this would prove operation of sensor is fine.
- when warm main coolant temp is reading 85 degrees C and EGR low temp sensor is reading 30.
EGR cooler is very hot to touch...hose from cooler down to temp sensor is cool.
-My problem would appear to be that the sensor is reading what it is seeing and the coolant is not hot at that point...never gets above 30 degrees C.
From the coolant system flow diagram it would appear the coolant from the low temperature rad side flows past EGR temp sensor, up the hose into egr cooler, cools the gas then flows into engine block???
I am curious what the operating temp of the low temp side should be??
Does this sound like the symptoms of a coolant or EGR thermostat??