coolant pump - mechanical failure?

[sQ5inSD]

Hello Forum - it has been a while but recently a new DTC has turned up for this:

18198 - Coolant pump
P1B1C 00 [045] - Mechanical malfunction

After some quick searching I learned this is typically a failure of a vacuum actuator that pulls on the vac line which is teed off the coolant pump itself. Since the coolant pump does not have any direct sensors this DTC code is somewhat misleading - at least to me. Anyway, I just wanted to see what others have found and what your solution was. For now, and until I have more time to properly fix the problem, I simply pulled the vac line off the coolant pump tee and plugged the line. The reason I did this was with that line connected the motor was overheating. The pump and T-stat are new this past March with only about 5k miles since. The cooling system has been modified with a Merc HX and when it was installed the system was properly filled/bled under vacuum. I have been driving it this way for about 500 miles since with no overheating issues. Has anyone else had this DTC and what did you do to correct it?

[92tsi]

I had an issue where the car would warm up properly and I could drive like an absolute grandpa, but as soon as I tried to drive normal it would instantly over heat. I believe it was the same code, but it was the solenoid that just happen to go bad.