Possible Deviation From Specified Value During The Pressure Test (12 Of 12)

Possible Deviation from Specified Value during the Pressure Test
High and low pressure normal The required cooling output is attained in the front heater and A/C unit evaporator (and on the evaporator for cooling the high-voltage components). The required cooling output is not attained on the heater core for the heat pump output.
Possible causes for the deviation from specified value and their solutions
One in or on the removed refrigerant circuit pressure/temperature sensor or temperature sensor sends incorrect values. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function. Refer to Component Location Overview - A/C System . One of the pumps or one of the valves in the coolant circuit for the high-voltage system or the engine is faulty or does not function correctly. Refer to Coolant Circuit . Activation of the A/C compressor is faulty. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function. If one of the valves installed in the refrigerant circuit is faulty or does not work correctly. Refer to Refrigerant Circuit . -- Check the measured values of the different pressure/temperature sensor and temperature sensor when operating the A/C system, and replace the components with incorrect measured values. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function. Refer to Component Location Overview - A/C System .-- Check the incorporation of the heat exchanger in the coolant circuit of the engine as well as the function and activation of the different pumps and valves. Refer to Coolant Circuit .-- Check the activation and function of the A/C compressor and service using the Vehicle Diagnostic Tester in the"Guided Fault Finding" function.-- Check the function and activation of the various valves and pressure/temperature sensors installed in the refrigerant circuit via the pressure distribution in the refrigerant circuit. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function. Refer to Refrigerant Circuit .-- Check the function and activation of the components for cooling the high-voltage components. Use the Vehicle Diagnostic Tester"Guided Fault Finding" for the air conditioner, the A/C Compressor and the Battery Regulation.-- If no malfunction can be determined, extract the refrigerant from the refrigerant circuit.-- Extract refrigerant from the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, DISCHARGING .-- If the extracted refrigerant quantity is significantly less than the specified capacity (more that 100 g (3.5 oz) less). Refer to Technical Data , and look for leaks and correct. Refer to LEAKS, FINDING .-- The extracted refrigerant quantity corresponds approximately to the specified capacity, check the activation of the A/C compressor and the installed shut-off valve again if no malfunction is determined. Refer to Refrigerant Circuit -- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .
Final Procedures
-- Charge the refrigerant circuit. Refer to REFRIGERANT CIRCUIT, CHARGING .-- Repeat the test. Refer to ELECTRICALLY-DRIVEN A/C COMPRESSOR, CHECKING PRESSURE WITH A/C SYSTEM SWITCHED ON .

NOTE:

If the required cooling output on the evaporator in the front heater and A/C unit (and on the evaporator for cooling the high-voltage battery is OK) and there is a concern due to insufficient heating performance on the heat exchanger for the heat pump operation. The cause may be in the high-voltage system coolant circuit or in the engine coolant circuit. If the pumps and valves in the high-voltage system coolant circuit is not activated correctly or its function is not OK via the evaporator (heat exchanger) for the high-voltage system components not enough heat energy is absorbed from the coolant. If the pumps and valves in the coolant circuit of the engine are not started correctly or its function are not OK via the heat exchanger for the heat pump function for absorbing the heat energy is not transferred to the coolant flowing to the heat exchanger in the heater and A/C unit. Use the Vehicle Diagnostic Tester in the"Guided Fault Finding" function. Refer to Coolant Circuit .

Refer to Possible Deviation From Specified Value During The Pressure Test (1 Of 12) for additional information.