Symptom:
The car has been overhauled due to accident, maintenance personnel in maintenance air conditioning system. Find air conditioning compressor can not pull operation, and the pipeline can only be added 80g refrigerant.
Diagnosis:
80g generated in the refrigerant pressure in the pipeline is sufficient to achieve co-operation of the air conditioning compressor suction requirements, from air-conditioning control panel, work situation, some of the electrical failure, since the control panel key light has an EC is lit. EC key has two basic functions, one pressing EC key, automatic air conditioning system into economic operation mode at this time cooling function is canceled; Second, when the electronic control system malfunction is detected in stored fault codes at the same time, EC key instructions Lights are activated lights.
Connect STAR diagnostic, electronic control system for air conditioning for self-diagnosis. 208348 models selected in the control module selected from the group "KLA" electrically controlled items. Inquiry fault information, displays the following contents: B1230EvaporatortemperaturesensorB10 / 6. Meaning of the evaporator temperature sensor B10 / 6 fault, currently exists.
B1231CoolanttemperatureserisorB11/4comesfromenginecorltroImodule. Meaning of the control module from the engine coolant temperature sensor B11 / 4 fails, does not currently exist.The benz mercedes diagnostic tool site:http://www.auto-diagnosis.com/pro.asp?id=157
B1232RefrigerantpressuresensorB12 meaning B12 refrigerant pressure sensor fault. Currently does not exist.
B1416HeaterwatercircIalationpumpA31ml. Meaning heater A31ml coolant circulation pump failure. Currently exists.
Clear DTCs function execution, close and turn the ignition switch once. Test. No change. Re-query fault information, the remaining DTCs B1230 and B1416. First, B1230 DTC detecting problems in the self-diagnosis menu, choose "Actualvalues" function View idling air conditioning system working condition when the evaporator temperature has been shown as -40 ℃. Explanation may be sensor failure B1O / 6 is damaged or caused by poor line connection. WIS database query "63.40Tableofcorlterltsfunctiondescriptionairconditioning (autoA / C)" group file, that the sensor is disposed in the bottom left of the dashboard air distribution box.
The driver's side trim panel removed, wiring harness under the dashboard layout was a bit messy. After a careful search. Finally found hidden in a vacant harness 2-pin wiring harness plug, air distribution box just has a 2-pin socket in the form of sensors. After re-docking clear fault codes, this time only B1416 fault code, indicating that the evaporator temperature sensor B10 / 6 is properly connected well. Start the engine, open the air conditioning and refrigeration, air conditioning compressor pull operation. Continue to add the right amount of refrigerant piping. Dashboard vents gradually blowing each breath. When the cooling effect is stable, once again in the "ActuaIvalues" diagnostic function to view the working conditions of air conditioning systems. Various data values are within the standard value range.
Although the automatic air conditioning system cooling function has returned to normal, but the B1416 DTC problem has not been resolved. Coolant circulation pump and automatic air-conditioning system heat function. Its function is to ensure that the engine operates at low speed, even when not running (ignition switch) a state where the cooling fluid heater lines can be normal cycle.
In order to find the exact components installed. WIS database query again, that the right side of the pump is installed in an engine coolant water pipes. Inspection found that the pump outlet harness breaking. Can not be repaired, only the replacement process is done. The new coolant circulation pump installed, use the B1416 diagnostic trouble codes cleared. Failure so far ruled out.
Fault summary:
Mercedes-Benz CLK230 Coupe type belongs, and W210, W220 and other chassis models compared to the automatic air conditioning system's configuration status is not advanced, not only is the air conditioning compressor electromagnetic clutch still use traditional forms of construction, but also in the air distribution control , still using the pneumatic tube on the throttle for a controlled manner. The air conditioning compressor is working, depending on the coolant temperature, the refrigerant pressure, refrigerant temperature, evaporator temperature these signals. Maintenance difficulty is not high, the maintenance staff can refer to a common model W140 chassis for maintenance operations.
The air conditioner cooling function failure conditions. Evaporator temperature signal is due to a disruption. In addition to the signal circuit, short circuit will cause the failure of the cooling function outside when the evaporator temperature reaches 1 ~ 3.5 ℃, automatic air conditioning control module N22 (with the control panel as one) will cut off the air conditioning compressor electromagnetic clutch working power, in order to prevent the evaporator icing.