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Alfa Romeo 159 Factory Service Manual (2005-2011)23 · Fault diagnosis
23 · Diagnostics

Passenger side temperature adjustment does not work

Make
Alfa Romeo
Model
159 Factory Service Manual
Year
2005–2011
Section
Climate control › Passenger side temperature adjustment does not work
Fault diagnosisPassenger side temperature adjustment does not work

PASSENGER SIDE TEMPERATURE ADJUSTMENT DOES NOT WORK

Automatic Air Conditioning

For the dual zone automatic climate control system only, when the desired temperature is set, passenger side, this temperature is not implemented.

1CHECK ON CORRECT OPERATION OF CLIMATE CONTROL NODEALL OKPROBLEMS ENCOUNTEREDACTION

With the engine running and the compressor switched off, set the control unit to the AUTO function (MONO button off) and adjust the temperature using the passenger side temperature knob from cold to hot.

Also select the recirculation button to the closed position and set the fan speed to 3-4 bars (display) and the distribution to front ventilation.

Using the Examiner, check that the engine temperature has reached at least 70°C.

Feel whether the air coming out of the vents varies in temperature (getting hotter).

Now carry out the operations to check the passenger compartment cooling function: with the engine running, the ambient temperature around 20°C and the compressor on, set the control unit to AUTO mode, adjust the passenger side temperature knob from hot to cold up to 16°C, the distribution to the front position, the fan speed to 3 bars and the outside air intake function.

After around 5 minutes in these conditions check, using the Examiner, that the temperature at the vents is decreasing: from the starting temperature of about 20°C (ambient temp.) gradually decreasing to a temperature of around 6°C.

Feel whether the air coming out of the vents varies in temperature (getting colder).

End of diagnosis1. The temperature of the air coming out of the vents does not get hotter.1. Move on to Step 2
2. The temperature of the air coming out of the vents does not get colder.2. Move on to Step 2
2CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION

Connect the Examiner diagnostic equipment and check:

  • that there are no errors at the passenger side air mixture actuator;
  • that there are no faults in the outside temperature sensor;
  • that there are no faults in the passenger compartment temperature sensor;
  • that there are no faults in the solar sensor.
Move on to Step 31. Short circuit to earth error at the air mixture actuator.1. Check that the Lin Bus cables are not caught between the metal parts (pay particular attention to the gearbox bolts) and move on to Step 4.
2. Short circuit to +12V error at the air mixture actuator.2. Check that the Lin Bus cables are not caught between the metal parts (pay particular attention to the gearbox bolts) and move on to Step 4.
3. Mechanical interference / stuck error.3. Move on to Step 6
4. Error at the outside temperature sensor.4. Move on to Step 4
5. Error at the passenger compartment temperature sensor.5. Move on to Step 4
6. Error at the solar sensor.6. Move on to Step 4
3CHECKS USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the Examiner diagnostic equipment connected, check the correct operation of the air mixture actuator through active diagnosisEnd of diagnosisAir mixture actuator not workingMove on to Step 4.
4ELECTRICAL CIRCUIT CHECKALL OKPROBLEMS ENCOUNTEREDACTION

Check the continuity/insulation of the electrical connection between the climate control node and the passenger side air mixture actuator and the treated air sensors and the outside temperature sensor and the passenger compartment sensor and the solar sensor.

Check whether the electrical wiring is loose, disconnect the connectors, visually inspect for any damage to the connectors reconnecting the connectors to the climate control node, the passenger side air mixture actuator, the outside temperature sensor and the solar sensor

Move on to Step 51.Electrical connection broken or not insulated.1.Restore the continuity/insulation of the electrical connection.
2. Electrical connection loose or damaged.2. Refit the electrical connections correctly.
3. Outside temperature sensor not working.

3. Replace the outside temperature sensor

Op. 7005R30 ELECTRICALLY CONTROLLED DOOR MIRROR (ONE) - R+R

4. Solar sensor not working.

4. Replace the solar sensor

Op. 5010D56 SOLAR SENSOR - R.R FOLLOWING ELECTRICAL SYSTEM CHECK

5. Passenger compartment temperature sensor.

5. Replace the climate control system control unit

Op. 5040D15

6. Air mixture actuator not working

6. Replace the mixture actuator

op. 5040D56

5CHECK ON CORRECT OPERATION OF MIXTURE ACTUATORALL OKPROBLEMS ENCOUNTEREDACTION

Check whether the electrical wiring connections are loose.

Disconnect and visually inspect for damage at the connector contacts and reconnect the connection to the motor mounting.

If it persists, before replacing the actuator, check its operation by manually activating the function that the actuator should carry out.

With the engine running, switch on the fan at maximum speed.

Place the flaps in the various distribution positions via the control/control unit (manually).

Check the air flow in the passenger compartment with your hand at the vents.

End of diagnosis1. Electrical connections loose or damaged.

1. Renew the electrical connections

See E6020 AIR CONDITIONING

2. There is no air flow intake into the passenger compartment through the vents.2. Move on to Step 6.
6CHECK ON IMPEDIMENTS TO THE ROTATION OF THE MIXTURE ACTUATORALL OKPROBLEMS ENCOUNTEREDACTION
Remove the actuator and check through the control unit that the actuator turns checking for the presence of mechanical impediments to its rotationEnd of diagnosis1.The actuator does not turn.

1.Replace the mixture actuator

op. 5040D56

2.Kinematic components of flaps broken/stuck.2.Replace the components that is faulty.

Parts & tools for this job For 2005 Alfa Romeo 159

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