A/C Unit, Integration in Engine Coolant Circuit

A/C Unit, Integration in Engine Coolant Circuit

CAUTION!
Even when the engine is cold, both pump/valve unit valves can be hot.

• When the ignition is on, the valves of the pump/valve unit (Left Heat Regulation Valve (N175) and Right Heat Regulation Valve (N176)) are continually activated depending on the temperature set at the Climatronic Control Module (J255) A/C control head. For this reason, the valve may be warm or hot even when the engine is cold.

• Both valves of the pump/valve unit (Left Heat Regulation Valve (N175) and Right Heat Regulation Valve (N176)) are reversed in left or right drive vehicles (differing connections ).

• If the Coolant Pump (V50) causes noise, check cooling system for complete bleeding (air in coolant circuit may cause noise) before removing pump-valve unit

• Under certain ambient conditions, if there are complaints of odd noises from the heat exchanger or poor heat output from the A/C system (an error may be stored at the Coolant Pump (V50) Check the pump/valve unit connection in the coolant circuit. If air bubbles are visible in the upper connection of the coolant expansion tank while the engine is running, also check the coolant expansion tank to ensure it is the correct version.

• Valves of pump valve unit are open when deenergized. If power supply or valve connection to the Climatronic Control Module (J255) A/C control head is interrupted, heat output of the A/C unit cannot be regulated (the A/C system heats constantly).