18 · Diagnostics

L10 Climate control unit does not cool

Make: Alfa Romeo
Model: 147 Factory Service Manual
Year: 2000–2002
Section: Climate control › L10 Climate control unit does not cool

‹ Prev L03 Climate control air flow irregular Next › L12 Climate control unit cools too much

Fault diagnosisL10 Climate control unit does not cool

L10 Climate control unit does not cool

The fan works properly and sends air into the interior compartment in accordance with set flow patterns, but this air remains at the external temperature and is not cooled.

NOTA: Cooling circuit activation enablement is controlled by the climate control and engine management control units. So if the air conditioning does not cool under particular conditions, this is correct.

Step	Test procedure	Result	Action
0	PRELIMINARY CHECKS Check the condition of the compressor drive belt	OK	Move onto step 1
		Tension incorrect	Replace the belt Op. 1092G10 End of diagnosis
		Deteriorated belt.	Replace the belt Op. 1092G10 End of diagnosis
1	CHECKING WITH DIAGNOSTIC EQUIPMENT Connect the diagnostic equipment (Examiner) to the diagnostic socket. Check that there are no faults in the engine management control unit Check that there are no faults in the climate control control unit	OK	Move onto step 2
		An error is detected in the control unit	Continue following the instructions for the diagnostic equipment End of diagnosis
		An error is detected in climate control unit	Continue following the instructions for the diagnostic equipment End of diagnosis
		Lack of communication with the climate control system control unit (CAN line error)	Restore connection between climate control system control unit and body computer connector Wiring diagram E6020 AIR CONDITIONER End of diagnosis
2	ACTIVE DIAGNOSIS WITH DIAGNOSTIC EQUIPMENT Using the diagnostic equipment (Examiner or other instruments) carry out active diagnosis on compressor activation relay operation	OK	Move onto step 3
		Compressor relay faulty	Replace the relay End of diagnosis
		4 stage pressure switch faulty	Move onto step 3
		Connections not correct	Restore the connection between the climate control control unit and the compressor coupling, via the 4 stage pressure switch and the engine management control unit: Wiring diagram E6020 AIR CONDITIONER Move onto step 4
3	4 STAGE PRESSURE SWITCH CHECK Check the 4 stage pressure switch	OK	Move onto step 4
3		4 stage pressure switch faulty	Replace the 4 stage pressure switch Op. 5040B14 End of diagnosis
4	CHECK COMPRESSOR ELECTRO-MAGNET COUPLING Check the operation of the compressor electro-magnet coupling.	OK	Move onto step 5
4		Defective compressor coupling.	Replace the compressor complete with coupling Op. 5040A34 End of diagnosis
5	CHECKING SYSTEM PRESSURE Checking system pressures:	OK	Move onto step 6
		High pressure does not increase or low pressure decreases too much: leaks in the circuit	Locate the leaks and restore the correct operation. End of diagnosis
		High pressure continues to rise: the compressor cooling fan does not cut in	If the fault is associated with that of excessive engine heating, See table D30 HIGH ENGINE TEMPERATURE End of diagnosis
6	CHECKING EVAPORATOR Check high and low pressure pipe seal, and condition of evaporator	OK	Move onto step 7
		Pipe from compressor to condenser damaged	Replace the pipe Op. 5040A50 End of diagnosis
		Pipe from filter to evaporator damaged	Replace the pipe Op. 5040A64 End of diagnosis
		Evaporator dirty	Replace the evaporator: Op. 5040C10 End of diagnosis
7	CHECKING CORRECT OPERATION Check that the fault is no longer present	OK	Incorrect selection of diagnostic procedure
7		Fault persists	Incorrect selection of diagnostic procedure

‹ Prev L03 Climate control air flow irregular Next › L12 Climate control unit cools too much

Parts & tools for this job For 2000 Alfa Romeo 147

Links open Amazon search results in a new tab. As an Amazon Associate I earn from qualifying purchases.