U1000 2005 Nissan Pathfinder -

Question

Is this expensive to fix or a major problem

Answer 1

P0128 the thermostat might be stuck open, and will need to be replaced if there are no coolant leaks or the coolant level is not low.

 

Nissan cars that has the U1000 the first thing to do is lossen all the ground connecters clean them with sand paper on the connector and body and retighen the bolts back 

There will be a few by the engine bay and will look like this lossen all the ground connecters clean them with sand paper on the connector and body and retighen the bolts back 

 

here is the service bulletin from nissan 

https://www.autocodes.com/uploads/nissan/NTB06-009a.pdf

You can also add a grounding kit to help the factory grounds since the factory grounds are thin and can lose connecting since you can rust and or have corrosion.