72571 - K20 FUEL LEVEL GAUGE NOT WORKING

With key on, the fuel level gauge on the instrument panel does not work (level indicated is not actual tank level);

the fuel level message is supplied by the "body computer node" and made available to the "instrument panel node" via the B-CAN network; the "Body Computer node" also sends a fuel level sensor error message. The operation should always be carried out with the engine switched off and the ignition switched off. If the operation is carried out with the engine switched on, but the ignition switched off, there may be a temporary incorrect fuel level reading due to the internal logic of the control system and not down to a system malfunction.

STEP	OPERATIONS TO BE CARRIED OUT	TEST RESULTS
0	PRELIMINARY CHECK	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the following with the engine running: the level pointer is not in contact with the 0 mark and the fuel reserve warning light is not flashing There are no error messages on the reconfigurable matrix	Move on to Step	1. Level pointer in contact and warning light flashing	Move on to Step
			2. Presence of fault message	Move on to Step
1	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Connect the Examiner diagnostic equipment to the diagnostic connector and check the following at the CAN: no control unit not activated; that there are no faulty control units; no control unit with faulty CAN line;	Move on to Step	Presence of faults	Continue following the instructions for the diagnostic equipment
2	CHECK USING DIAGNOSTIC EQUIPMENT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Keeping the Examiner diagnostic equipment connected to the diagnostic connector, check the following at the instrument panel node:in active diagnosis ambient operation of the fuel level gauge	Move on to Step	Pointer does not move	Replace instrument panel    See in Op. 5560B11 ANALOGUE CONTROL PANEL - R.R. or Replace
3	CHECK FUEL LEVEL SENSOR	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check fuel level sensor operation	Move on to Step	Sensor not working	Replace the fuel pump assembly    See in Op. 1040A70 SUBMERGED PUMP ASSEMBLY complete with level gauge - R.R.
4	CHECK ELECTRICAL CIRCUIT	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check the continuity/insulation of the lead between fuel level sensor and body computer (Wiring Diagram ) E4010 INSTRUMENT PANEL	Move on to Step	Leads interrupted or not insulated	Restore continuity or insulation (Wiring Diagram ) E4010 INSTRUMENT PANEL
5	CHECK ON CORRECT OPERATION	ALL OK	PROBLEMS ENCOUNTERED	ACTION
	Check that the fault is no longer present		Fault persists	Replace body computer    See in Op. 5505A32 BODY COMPUTER - R.R.