P0645 Conditioner relay control

			Test results
0	COMPONENT CONCERNED	PRELIMINARY CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Engine management control unit	Check if "Overtemperature" is shown in the error details	Go to Step 1	The error detail is "Overtemperature"	Go to Step 5
1	COMPONENT CONCERNED	ELECTRICAL CONNECTION CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Air conditioning relay wiring	Check for the presence of short circuit to Vbatt See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT	Go to Step 2	Presence of short circuit to Vbatt.	Restore correct insulation to battery positive
2	COMPONENT CONCERNED	ELECTRICAL CONNECTION CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Air conditioning relay wiring	Check for short circuits to earth See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT	Go to Step 3	Presence of short circuit to earth	Restore correct insulation to earth
3	COMPONENT CONCERNED	ELECTRICAL CONNECTION CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Air conditioning relay wiring	Check for an open circuit See E5050 DIESEL ENGINES ELECTRONIC MANAGEMENT	Go to Step 4	Presence of open circuit	Restore the correct connections
4	COMPONENT CONCERNED	CHECK USING DIAGNOSIS EQUIPMENT	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Conditioner relay	Connect the diagnosis equipment to the engine management control unit and use Active Diagnosis to check whether the conditioner relay control is working correctly	Go to Step 5	Relay faulty	Replace the air conditioning main relay
5	COMPONENT CONCERNED	ENGINE MANAGEMENT CONTROL UNIT CHECK	OK (NO FAULTS DETECTED)	FAULT DETECTED	OPERATION
	Engine management control unit	Check that the engine management control unit is working correctly	End of diagnosis	Engine management control unit not working properly	Replace the engine management control unit Op. 1060G80