Audi A4/A5/A6/A7/Q5/Q7/TT - Loss of power in heating/air-conditioning systems | HELLA



Model years: 2011 – 2014

Loss of power in heating/air-conditioning systems

Should the vehicles mentioned above experience a loss of heating and/or air-conditioning power, water entry into the wiring harness may be the cause.

Due to defective coolant control valves (heating, transmission), coolant can leak and enter the connectors and wiring. This results in electric defects and corrosion. Other defects will frequently occur throughout:

  • Coolant warning lamp flashes
  • Motor temperature high
  • Motor goes into emergency mode
  • Error code P2753/P2755

For eliminating the problem, check all coolant valves with their plugs and electric lines and replace where necessary.

The following vehicle models can be affected:

Model: year:


2010 - 2013


2011 - 2013

A5 convertible

2012 - 2014


2012 - 2014


2012 - 2014


2012 - 2014


2012 - 2013


2012 - 2013

Important safety note Technical information and practical tips have been compiled by HELLA in order to provide professional support to vehicle workshops in their day-to-day work. The information provided on this website is intended for use by suitably qualified personnel only. Reprinting, distribution, reproduction, exploitation in any form or disclosure of the contents of this document, even in part, is prohibited without our express, written approval and indication of the source. The schematic illustrations, pictures and descriptions serve only for the purposes of explanation and representation of the instructions and cannot be used as a basis for installation or assembly work. All rights reserved.