Engine Coolant Circuit, Bleeding: Prerequisite

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Since only a small amount of air entered the coolant circuit during installation of the heat exchanger for the heater in the A/C unit, the Coolant Recirculation Pump -V50-, the Coolant Shut-Off Valve -N82-, etc. and the circuit was charged again during installation of the components, only a small amount of air is in the coolant circuit. Therefore, it is sufficient to set the A/C system to maximum heating output when the engine is at operating temperature (so that the Coolant Recirculation Pump -V50- is activated) and to run the engine for several minutes at a high idling speed (approximately 2000 RPM) to completely bleed the coolant circuit.
When bleeding the coolant circuit, take special care to ensure complete bleeding of the heater core. If air bubbles remain in the heater core, customer complaints may be received about lack of heating output in winter or differences in temperature of air flowing out of vents with same setting in control mode. Refer to A/C SYSTEM TEMPERATURE DOOR HEAT OUTPUT ACTIVATION, CHECKING .