Mercedes-Benz CLK320 Air Conditioning Refrigerant Temperature Sensor Replacement Cost

Air conditioning systems cool the interior of the vehicle by processing refrigerant in a closed loop. Throughout this closed loop, refrigerant is changed from hot to cold, high pressure and low pressure, and high heat and low heat. The amount of change that the air conditioning control module sees in these phases allow it to determine if the air conditioning system is working properly. For this purpose, many systems use refrigerant temperature sensors to ensure that the temperature of the refrigerant is correct in different parts of the refrigerant system.

The temperature sensor for the air conditioning refrigerant system will be screwed into a major component or a refrigerant line. There it will have direct contact with the refrigerant in the system and changes in refrigerant temperature will cause the sensor to send higher or lower voltage to the control module. This voltage will be interpreted by the control module, translated into a temperature, and the control module uses this information to determine if the system is running efficiently.

A failed refrigerant temperature sensor will cause the air conditioner to cease functioning, and a warning message or blinking a/c light will alert the driver to a found deficiency. There is a chance that the sensor may not register changes in temperature, but these changes would cause the refrigerant pressure sensors to react with the same symptoms before catastrophic failure occurs.

There is no necessity to repair the air conditioner immediately. Replacement is based on convenience and comfort alone. In some locations, the heat outside may be sufficient to consider using a vehicle with no air conditioner a health risk for children or seniors, so this would raise safety concerns.

Temperature sensors are typically long lived. They are installed in a safe location, have no moving parts, and include only simple circuits. If the temperature sensor reports a failure, it is most likely performing its job correctly, and there will be an issue in the refrigerant system causing the refrigerant to cool excessively or become too hot.

The first step to identifying an issue with the temperature sensor is to identify if it is functioning properly. This can be done by measuring the temperature of the sensor or refrigerant line and comparing those readings to the sensor readings in the vehicle. If the readings match, the sensor is likely functioning properly. However, if an incongruence exists between the readings, the sensor will be replaced once the circuit is verified to function properly.

Replacing these refrigerant temperature sensor requires the system to be evacuated of all refrigerant, the sensor unscrewed and replaced, and then recharging the system. If the vehicle uses an orifice tube, the technician will likely recommend replacing it while the system is discharged, and if signs of water contamination are present, the receiver drier or accumulator should be replaced as well. Finally, the system can be recharged, and the air conditioning system will be tested to prove the repair.

Air conditioning issues tend to have the same symptoms, but there are many components that may fail and lead to these symptoms. This being the case, it is imperative that the air conditioning system be diagnosed properly before replacing components. This will prevent frustration and frivolous costs.

Not all vehicles have an refrigerant temperature sensors. Some will only deactivate the system based on system pressure at other positions, so diagnosis is a must. It may be the most helpful to have the service manual for the vehicle on hand to allow proper diagnostic procedures to be taken.

This is not a repair that can be performed by the DIY mechanic unless refrigerant recovery equipment and vacuum and recharge equipment are on hand. Since this equipment is very costly, the most cost effective option is to have the air conditioner serviced by a professional.