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Fiat Croma Factory Service Manual (2005-2010)22 · Fault diagnosis
22 · Diagnostics

Climate control not heating

Make
Fiat
Model
Croma Factory Service Manual
Year
2005–2010
Section
Climate control › Climate control not heating
Fault diagnosisClimate control not heating

CLIMATE CONTROL NOT HEATING

The climate control is working properly and sends air according to the preset flows but this air does not guarantee the required heating.

PRELIMINARY CHECKALL OKPROBLEMS ENCOUNTEREDACTION
0Check that the engine coolant level is within the preset levels and that the refrigerant fluid circulates correctly in the systemMove on to Step 11.Engine coolant level too low.

1,Restore the correct level

Op. 0010T84 COOLANT FOR AIR CONDITIONING SYSTEM - DEHYDRATE AND REPRESSURIZE

check for leaks

2.Coolant does not circulate correctly: thermostat valve operationg incorrectly.

2.Perform diagnosis

See table K025 ENGINE COOLANT TEMPERATURE GAUGE NOT WORKING

CHECK ON CORRECT CLIMATE CONTROL SYSTEM OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
1

With the engine on and the compressor off, in manual mode with the temperature knob at the maximum hot HI position.

Also set the recirculation button to the closed position and set the fan speed to 6 bars (display) and the distribution to front ventilation.

Use the diagnostic tester to check that the engine temperature reaches at least 70 °C.

Check that the air temperature at the front distribution outlet is greater than 60 °C.

End of diagnosisThe temperature of the air coming out of the vents is not as desired.Move on to Step 2
CHECK ON CORRECT CLIMATE CONTROL SYSTEM OPERATIONALL OKPROBLEMS ENCOUNTEREDACTION
1

With the engine on and the compressor off, in manual mode with the temperature knob at the maximum hot HI position.

Also set the recirculation button to the closed position and set the fan speed to the 3rd setting and the distribution to front ventilation.

Use the diagnostic tester to check that the engine temperature reaches at least 70 °C.

Check that the air temperature at the front distribution outlet is greater than 60 °C.

End of diagnosisThe temperature of the air coming out of the vents is not as desired.Move on to Step 2
CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
2

Connect the diagnostic equipment and check:

  • that there are no errors at the air mixing actuators
  • that there are no faults in the engine temperature sensor
End of diagnosis1. Short circuit error at the air mixing actuators1.Move on to Step 3
2. Error in the engine temperature sensor2. Continue as instructed by the diagnostic equipment
CHECK USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
2Connect the Examiner diagnostic equipment and check that there are no errors in the engine temperature sensorMove on to Step 5Error in the engine temperature sensorContinue as described by the diagnostic equipment
ELECTRICAL CIRCUIT CHECKALL OKPROBLEMS ENCOUNTEREDACTION
3

Check whether the electrical wiring connections are loose:

Disconnect and check for damage in the connector contacts/reconnect the connection to the actuator.

Check the continuity/insulation of the electrical connection:

  • of the air mixing actuator/s.
  • the connection on the control unit.
Move on to Step 41. Electrical connections loose or damaged.

1. Renew the electrical connections

See E6020 AIR CONDITIONING

2. Electrical connection broken or not insulated.

2. Restore the continuity/insulation of the electrical connection

See E6020 AIR CONDITIONING

CHECK ON CORRECT OPERATION USING DIAGNOSTIC EQUIPMENTALL OKPROBLEMS ENCOUNTEREDACTION
4Check for persistent errors in the air mixer actuatorsEnd of diagnosisAir mixing actuator errorMove on to Step 5
CHECK THE CORRECT OPERATION OF THE MIXER ACTUATOR DRIVE CHAINALL OKPROBLEMS ENCOUNTEREDACTION
5

Visually check the correct operation of the mixer actuator from the climate control unit temperature control knob.

Check whether the control on the control unit is interrupted by checking the electrical continuity in accordance with the test.

See Test 5040DH SEQUENTIAL PROCEDURE FOR CHECKING OPERATION OF MIXTURE AND DISTRIBUTION ACTUATORS

Move on to Step 61. Incorrect operation of actuator

1. Replace the mixer actuator

Op. 5040D77 AIR CONDITIONER MIXER FLAP CONTROL MOTOR - R R

2. Physical impediment to flap rotation2. Replace the control unit
3. Incorrect operation of the control actuator on the climate control unit

3. Replace the climate control system control unit

Op. 5040D18 AIR CONDITIONING CONTROL UNIT - R.R.

CHECK THE CORRECT OPERATION OF THE MIXER ACTUATOR DRIVE CHAINALL OKPROBLEMS ENCOUNTEREDACTION
5

Visually check the correct operation of the mixer actuator from the climate control unit temperature control knob.

Check whether the control on the control unit is interrupted by checking the electrical continuity in accordance with the test.

See Test 5040DH SEQUENTIAL PROCEDURE FOR CHECKING OPERATION OF MIXTURE AND DISTRIBUTION ACTUATORS

Move on to Step 61. Incorrect operation of actuator

1. Replace the mixer actuator

Op. 5040D77 AIR CONDITIONER MIXER FLAP CONTROL MOTOR - R R

2. Physical impediment to flap rotation2. Replace the control unit
3. Incorrect operation of the control actuator on the climate control unit

3. Replace the climate control system control unit

Op. 5040D18 AIR CONDITIONING CONTROL UNIT - R.R.

AIR MIXTURE ACTUATOR FLAP CHECKALL OKPROBLEMS ENCOUNTEREDACTION
6Check that the air mixture actuator flap completes its travel without any impedimentEnd of diagnosis1. Flap travel incomplete1. Free the air mixer actuator flap from the impediment
2. Flap damaged2. Replace the flap
3. Drive chain/gears damaged.3. Restore the correct drive chain.

Parts & tools for this job For 2005 Fiat Croma

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