23 · Diagnostics

Rear passenger temperature adjustment not working

Make: Alfa Romeo
Model: Brera and Spider Factory Service Manual
Year: 2005–2010
Section: Climate control › Rear passenger temperature adjustment not working

‹ Prev Passenger side temperature adjustment does not work Next › Air heating is not activated with low outside temperature

Fault diagnosisRear passenger temperature adjustment not working

REAR PASSENGER TEMPERATURE ADJUSTMENT NOT WORKING

Automatic climate control

For the triple zone automatic climate control system only, when the desired temperature for the rear pasengers is set, this temperature is not implemented.

1	CHECK ON CORRECT OPERATION OF CLIMATE CONTROL NODE	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	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 rear 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 rear passenger 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 about 5 minutes in these conditions, check using the Examiner that the temperature values for the rear vents have gradually decreased from the initial temperature of about 20°C (ambient temp.) to a temperature of around 6°C. Feel whether the air coming out of the vents varies in temperature (getting colder).	End of diagnosis	1. The temperature of the air coming out of the vents does not get hotter.	1. Move on to Step 2
		End of diagnosis	2. The temperature of the air coming out of the vents does not get colder.	2. Move on to Step 2
2	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the Examiner diagnostic equipment and check: that there are no errors at the rear passenger 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 3	1. Short circuit to earth error at the rear air mixture actuator.	1. 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 4.
			2. Short circuit to +12V error at the rear air mixture 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 4.
			3. Mechanical interference / stuck error at the rear air mixture actuator	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
3	CHECKS USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the Examiner diagnostic equipment connected, check the correct operation of the air mixture actuator through active diagnosis	End of diagnosis	Air mixture actuator not working	Move on to Step 4.
4	ELECTRICAL CIRCUIT CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the continuity/insulation of the electrical connection between the climate control node and the rear passenger 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 rear passenger air mixture actuator, the outside temperature sensor and the solar sensor.	Move on to Step 5	1.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. 5040D79 MOTOR (ONE) CONTROLLING LH AIR CONDITIONER DISTRIBUTION/MIXER FLAPS R R WITH AIR CONDITIONER HOUSING REMOVED
			5. Passenger compartment temperature sensor not working.	5. Replace the climate control system control unit Op. 5040D18 AIR CONDITIONING CONTROL UNIT - R.R.
			6. Rear mixture actuator not working.	6. Replace the rear mixture actuator.
5	CHECK ON CORRECT OPERATION OF MIXTURE ACTUATOR	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	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 diagnosis	1. Electrical connections loose or damaged.	1. Renew the electrical connections See E6020 AIR CONDITIONING
		End of diagnosis	2. There is no air flow intake into the passenger compartment through the vents.	2. Move on to Step 6.
6	CHECK ON IMPEDIMENTS TO THE ROTATION OF THE MIXTURE ACTUATOR	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Remove the actuator and check through the control unit that the actuator turns checking for the presence of mechanical impediments to its rotation	End of diagnosis	1.The actuator does not turn.	1.Replace the mixture actuator Op. 5040D79 MOTOR (ONE) CONTROLLING LH AIR CONDITIONER DISTRIBUTION/MIXER FLAPS R R WITH AIR CONDITIONER HOUSING REMOVED
		End of diagnosis	2.Kinematic components or flaps broken/stuck.	2.Replace the component that is faulty.

‹ Prev Passenger side temperature adjustment does not work Next › Air heating is not activated with low outside temperature

Parts & tools for this job For 2005 Alfa Romeo Brera

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