939003635 - K021 FUEL RESERVE WARNING LIGHT NOT WORKING

With the ignition ON, the fuel reserve warning light does not come on when the tank is in the reserve condition

The fuel level message is supplied by the "body computer node" and is made available to the "instrument panel node" via the B-CAN and to the gauge via a serial line.

The "Body Computer node" also sends the fuel level sensor error message

1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the Examiner diagnostic equipment to the diagnostic socket.Check that there are no faults in the Body Computer	Move on to Step 2	Sensor with broken circuit, sensor short circuited, value implausible/not consistent with actual fuel level	Continue as described by the diagnostic equipment
2	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the Examiner equipment connected to the diagnostic socket, check the operation of the fuel reserve warning light in active diagnosis	Move on to Step 3	1.The warning light does not come because the serial line is interrupted	1.Renew serial line
			2.Instrument power supply interrupted	2.Restore power supply
			3.Instrument defective	3.Replace instrument panel    Op. 5560B10 CONTROL PANEL - R+R
3	CHECK FUEL LEVEL SENSOR	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check fuel level sensor operation by carrying out the Test    See Test 1040AC FUEL LEVEL GAUGE CHECK	Move on to Step 4	Sensor not working.	Replace the fuel pump assembly    Op. 1040A70 SUBMERGED PUMP ASSEMBLY COMPLETE WITH LEVEL GAUGE CONTROL - R + R
4	ELECTRICAL CIRCUIT CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the continuity/insulation of the lead between fuel level sensor and Body Computer    See E4010 INSTRUMENT PANEL	Move on to Step 5	Connections broken/not insulated	Restore cable continuity/insulation
5	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present	End of diagnosis	The fault persists	Replace Body Computer    Op. 5505A32 BODY COMPUTER - R.R