How to deal with Citroen C3 climate and radiator fan error?
I want to share my experience troubleshoot climate and radiator fan issue with more people.
I have 2004 C3 HDI, with smart fan 1253h3, has ABS with no esp and automatic climate. When I switch climate on or heat bar 3 dash warms and beeps 3 times and all the heat lights come on. I noticed that if engine warning light on everything is ok when engine warning light turn off on the dashboard fan not cuts in and the problem comes back. I changed engine heat sensor, thermostat, controlled all wiring (can bus wiring, fan power cables), changed relay. But nothing solved the problem. Then I went to C3 forum for help, and a member told me to use Lexia-3 to pull up any error codes before changing parts and it can help guide to the point of the problem.
On slow speed actuator it says faulty actuator. But sometimes fan cuts in. An interesting alternative description for P0485 is Cooling Fan Power/Ground Circuit Malfunction. It might be a fan or an ECU, I am not sure from a P code. But it is easier to try a new fan than try a new ECU. So I replaced the fan, and the clear the climate control problem is fixed.