Original fault, overheating.
Timing belt, w pump and stat replaced(not faulty but over due).
Radiator changed, was partially blocked. Major improvement but still some overheating.
Bypassed EGR cooler circuit(will replace egr when fix confirmed). no more overheating.
No excess pressure in cooling system.
Engine temp sensor replaced, no change.
Electric coolant pump changed, no change
Cooling fan overrunning, approx 10mins at idle, slows in steps over that period.
Temp gauge shows approx 90 all time engine warm.
Fault codes refer to cruise control.

Read of a software update for EGR. Would this be cause of fan over running?

Software(from VCDS) 03L 997 557L
Hardware 03L 906 023A

help!