A software fix apparently did not completely address pump overheating issues.
Audi has issued a second recall for nearly 343,000 vehicles to address ongoing problems with overheating coolant pumps.
The company in 2016 rolled out a software update to switch off coolant pumps that have become blocked, theoretically preventing the pumps from becoming overheated and causing fires.
Some cars with reprogrammed control modules continued to experience overheating problems as engineers continued to move forward with root-cause analysis, eventually discovering that both debris blockage and moisture could cause the pumps to fail.
Audi recently decided that coolant pumps must be replaced to fully address the safety concerns.
The campaign affects 2.0T engines used in the 2013-2017 A5, 2012-2015 A6, 2013-2016 A4 and 2013-2017 Q5.