939003708 - L057 WINDSCREEN MISTING WITH THE FORMATION OF CONDENSATION (Automatic Air Conditioning)

On vehicles equipped with a windscreen demisting sensor, it does not work and the windscreen does not demist with the air conditioning on when there is condensation.
1CHECK ON CORRECT OPERATION OF SENSORALL OKPROBLEMS ENCOUNTEREDACTION
Check that the demisting sensor lens in the windscreen is not obstructed by foreign bodies or that it is not dirty or marked and that the windscreen is not dirty.Move on to Step 21.Demisting sensor lens obscured by foreign bodies.1. Remove the foreign bodies from the sensor.
2. Demisting sensor lens dirty.2. Clean the sensor lens.
3. Demisting sensor lens scratched.3. Replace the demisting sensorOp. 5010D36 DEMISTING SENSOR R R FOLLOWING ELECTRICAL CIRCUIT CHECK
4. Windscreen dirty.2. Clean the windscreen.
2CHECK THAT THE PROXY HAS BEEN CARRIED OUT FOR THE SYSTEMALL OKPROBLEMS ENCOUNTEREDACTION
Connect the Examiner diagnostic equipment and check that the Proxy has been carried out for the system to recognize the sensor.Move on to Step 3Proxy not carried out for the system to recognize the sensor.Carry out the Proxy for the system.
3CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Connect the Examiner diagnostic equipment and check that there are no errors at the windscreen demisting sensor.If the result is negative, carry out the    See Test 5040DB Check windscreen demister sensor operationMove on to Step 41.Error in the demisting sensor: 0% or 100% according to the    See Test 5040DB Check windscreen demister sensor operation1. Move on to Step 5
2. Error in the demisting sensor: 90% or 80% according to the    See Test 5040DB Check windscreen demister sensor operation2. Move on to Step 6
3. Error in the demisting sensor: 10% according to the    See Test 5040DB Check windscreen demister sensor operation3. Replace the demisting sensorOp. 5010D36
4CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the Examiner diagnostic equipment connected, check:

  • that there are no errors at the Climate Control Node;
  • that there are no errors at the timing actuator.
Move on to Step 81. Error at climate control node.1. Move on to Step 5.
2. Short circuit to earth error at the distribution actuator.2. Check that the Lin Bus cables are not caught between the metal parts (pay special attention to the gearbox bolts) and move on to Step 8.
3. Short circuit to +12V error at the distribution actuator.3. Check that the Lin Bus cables are not caught between the metal parts (pay special attention to the gearbox bolts) and move on to Step 8.
4. Mechanical interference/stuck error.4. Move on to Step 10.
5CHECKS USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the Examiner diagnostic equipment connected, check the correct operation of the air mixture actuator through active diagnosisMove on to Step 6.Air mixture actuator not workingMove on to Step 8.
6CHECK ON DEMISTING SENSOR ELECTRICAL CONNECTIONSALL OKPROBLEMS ENCOUNTEREDACTION
Check whether the windscreen demisting sensor electrical wiring connections are loose or damaged, disconnect/reconnect the wiring. Check the continuity/insulation of the sensor electrical wiring.Move on to Step 71. Electrical connections loose or damaged.1. Restore correct wiring.
2. Sensor wiring broken or short circuited.2. Restore correct wiring.
7CHECK ON THE CORRECT INSTALLATION OF THE DEMISTING SENSORALL OKPROBLEMS ENCOUNTEREDACTION
Check that the demisting sensor is correctly positioned in its housing.Move on to Step 8Demisting sensor not correctly positioned.Refit the sensor in the correct position.
8CHECK ELECTRICAL CONNECTIONSALL OKPROBLEMS ENCOUNTEREDACTION
Check whether the electrical wiring connections between the Climate Control Node and the distribution actuator are loose/damaged.Disconnect/reconnect the connection to the Climate Control Node and to the actuator and to the demisting sensor.Check the continuity/insulation of the electrical connection between the Climate Control Node and the distribution actuator and the sensor.Move on to Step 91.Electrical connections loose/damaged1. Restore the correct wiring.
2.Electrical connection broken or not insulated.2. Restore the continuity/insulation of the electrical connection.
9CHECK ON CORRECT OPERATION OF DISTRIBUTION ACTUATORALL OKPROBLEMS ENCOUNTEREDACTION
Check the operation activating the function that the actuator should carry out manually.With the vehicle moving, switch on the passenger compartment fan at the maximum speed (6 bars on the display), place the flaps in the max. def. position using the control/control unit (manually) and check the air flow in the passenger compartment by placing your hand over the vents.End of diagnosisFlow of air to the windscreen insufficient.Replace the distribution actuator Op.  
10DISTRIBUTION ACTUATOR FLAP CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Check that the actuator flap completes its travel without any impediment.End of diagnosis1. Flap travel incomplete.1. Free the air mixture actuator flap from the impediment.
2. Flap damaged.2. Replace the flap.
3. Kinematic mechanism / components damaged.3. Repair kinematic mechanism.