Note | For all complaints marked with a * → Chapter. |
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| The cooling has failed completely. * |
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| Insufficient cooling at all vehicle speeds and engine speeds.* |
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| No cooling or insufficient cooling after a distance of several kilometres has been driven. * |
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| The air conditioner compressor, the air conditioning system magnetic clutch -N25- or the air conditioner compressor regulating valve -N280- have been switched off by low-pressure switch for magnetic clutch -F73-, high-pressure switch for magnetic clutch -F118-, air conditioning system pressure switch -F129- or by operating and display unit for Climatronic air conditioning system -E87- or Climatronic control unit -J255- because pressure was too high or too low.* * |
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| No fresh air flow, or very much reduced fresh air flow after driving some distance (evaporator iced up). * |
| In addition the following complaints may also arise: |
| The air conditioner compressor is noisy. |
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| Tighten the securing screws for the air conditioner compressor and the air conditioner compressor bracket using a torque wrench. |
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| Check routing of refrigerant pipes; they must not touch other components and must be installed without tension (adjust if necessary). |
| Noises (refrigerant hammering) occur immediately after the air conditioning is switched on and/or in a curve or when the brakes are applied: |
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| Discharge refrigerant circuit, evacuate and charge again (too much refrigerant in circuit). |
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| Excess refrigerant oil in the circuit may also cause this problem (e.g. if the refrigerant oil level was not checked after the air conditioner compressor was renewed). The refrigerant circuit must be purged with R134a refrigerant for this complaint → Chapter. |
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| The refrigerant must be drained from the air conditioner compressor via the drain plug . To facilitate this process, turn the air conditioner compressor over by hand at the poly V-belt pulley or coupling disc of the magnetic coupling. Then fill refrigerant circuit with total amount of refrigerant oil (50 g direct into air conditioner compressor) according to → vehicle-specific workshop manual. |
| Water sprays out of the air vents (dash panel or footwell) although the air conditioning system otherwise works properly: |
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| Check that the condensation water drain is properly routed; it must not be pinched or kinked. |
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| The condensed water drain valve must not be hindered in its operation by wax or underbody sealant and must open and close properly. |
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| Check the plenum chamber cover; it must be undamaged and be installed correctly (no water must flow into the evaporator). |
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| Check water drains in plenum chamber; they must not be blocked (e.g. by leaves). |
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