2000 CLK430 AUX Circulating Pump - Aux coolant pump
 

When is the aux electric coolant pump supposed to run? On my 2000 CLK430 I've been getting and clearing a B1416 error on the climate controller. My pump does not run when the car is turned off or when its on. The only time it works when the REST button is pressed (residual heat cabin function). Temps are in the 60's. Is this normal - I though the pump should run when the car is turned off and run for 10 minutes.

Any help would be appreciated. Thanks.

It's only supposed to run with the REST and when heat is on full.