How to force-drive the radiator cooling fan with VCDS... ?

( 2008 ) Audi A4 "B7"

I want to force-drive the external cooling fan with VCDS.
Both through the 08-Auto HVAC module and the 01-Engine module.
How do I do this ?
( This to exclude errors in the Radiator fan control module and to the fan itself )

There should be a Selective Output Test in 01-Engine for: "Fan 1 Control Circuit".

Looks like your HVAC and Instrument Cluster only only support Sequential Output Tests (scroll up the page linked above). That means the only way to find out what's in 'em is to run through the sequence. Instrument Clusters of that vintage often had an "ECT Overheat" test that would kick the fans to full speed.

-Uwe-

Hi there,

I just wanted to add some important notes, the ignition key should be on, the engine should be off (no running) and the fans will typically 'ramp up'(activate) from a 0% to 100%. If there are two fans, both should operate during the tests.

It maybe necessary to start the engine and then shut it down, wait a few seconds and the turn the key back on and re-select the [Output Tests] if the tests do not run or you want to run the tests again.

Hope this helps,

drpeter