Air Pump

Air Pump:

Check function:

The magnetic clutch for the air pump is activated below an engine temperature of 40° C (<30° C for cat. provision) and at an engine speed < 4600 rpm (< 2600 rpm for cat. provision). Activation takes place by means of the air pump relay in the E-box for approx. 2.5 min (12 min for cat. provision).

Check vacuum supply for the changeover valve (approx. 200 mbar), otherwise the shut-off valves does not open.

A hose can be attached to the air cleaner housing (below the coolant expansion tank) to check whether the air pump is operating. The vacuum can be felt with the hand when the air pump is running.