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

Climate control recirculation (automatic mode) not working

Make
Alfa Romeo
Model
159 Factory Service Manual
Year
2005–2011
Section
Climate control › Climate control recirculation (automatic mode) not working
Fault diagnosisClimate control recirculation (automatic mode) not working

CLIMATE CONTROL RECIRCULATION (AUTOMATIC MODE) NOT WORKING

Automatic Air Conditioning

For vehicles with AQS sensors only, the recirculation is not closed automatically if there is pollution (CO, NO2 toxic gases only)

1CHECK ON CORRECT OPERATION OF CLIMATE CONTROL NODEALL OKPROBLEMS ENCOUNTEREDACTION

With the engine started, set the climate control system control unit to the AUTO position, adjust the temperature knob to reach 22°C, set the fan speed at 6 bars, then press the recirculation button (check that the recirculation warning light comes on).

Then check that the air flow varies during the opening/closing of the flap by feeling.

Also locate the grille in the engine compartment for the air intake casing and check the air intake when switching from recirculation to outside air intake.

"When the control unit is set to the FULL AUTO function and the outside temperature is below 3°C the air intake flap opens automatically to prevent the windscreen from misting up". Note:" The AQS sensor is disabled at outside temperatures below 8°C".

Move on to Step 21.The LED with the recirculation symbol does not light up1. Move on to Step 4
2. The recirculation symbol LED comes on (but the recirculation does not operate).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 air recirculation actuator;
  • that there are no faults in the AQS sensor.
Move on to Step 31. Short circuit to earth error.1. Move on to Step 5
2. Short circuit to +12V error.2. Move on to Step 5
3. Mechanical interference / stuck error.3. Move on to Step 7
4. Errors in the AQS sensor4. Move on to Step 4
3CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
Keeping the Examiner diagnostic equipment connected, check the correct operation of the air recirculation through active diagnosisMove on to Step 4Air recirculation actuator not workingMove on to Step 5
4CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION

Check that the recirculation flap is working properly in automatic mode by carrying out the "Pollution sensor test".

If the result is negative, carry out the

See Test 5040DD Check operation of pollution sensor (AQS)

End of diagnosis1.AQS sensor not working

1.Replace AQS sensor

Op. 5010D72 AIR QUALITY SENSOR - R.R. FOLLOWING ELECTRICAL CIRCUIT CHECK

2. Wiring faulty.2. Repair the wiring
5CHECK ELECTRICAL CONNECTIONSALL OKPROBLEMS ENCOUNTEREDACTION

Check whether the electrical wiring connections are loose.

Remove the control unit from the panel mount, disconnect the wiring connector from the control unit and check visually for any damage to the connector and reconnect correctly to check for false contacts.

Remove the oddments pocket and disconnect the connector, inspecting visually for any damage to it and reconnect the electrical connector to the actuator.

Move on to Step 6Electrical wiring connections loose or damaged.Restore the correct wiring connections.
6CHECK ON CORRECT OPERATION OF RECIRCULATION ACTUATORALL OKPROBLEMS ENCOUNTEREDACTION

Then proceed as follows: with the engine running, switch on the recirculation air intake function manually with the fan at the maximum speed.

If the actuator works and the flap is driven, check whether the air flow rate varies during the movement by feeling it.

Deactivate the function restoring the actuator to the original condition.

Identify the air intake casing grille on the vehicle and check the air intake in the shift from recirculation to outside air and the other way round by feeling with your hand.

Move on to Step 7Incorrect operation of recirculation actuator.

Replace the recirculation actuator

Op. 5040D53

7RECIRCULATION ACTUATOR FLAP CHECKALL OKPROBLEMS ENCOUNTEREDACTION
Visually inspect that the air recirculation actuator flap completes its travel without any hinderance.End of diagnosis1. Flap travel incomplete.1.Free from air recirculation actuator flap from the impediment.
2. Flap damaged.2.Replace the flap.
3. Kinematic mechanism damaged.3.Repair kinematic mechanism.

Parts & tools for this job For 2005 Alfa Romeo 159

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