125000584 - K140 FUEL RESERVE WARNING LIGHT ON CONSTANTLY

The Engine Management Node sends the message via the C-CAN to the Body Computer which makes it available to the Instrument Panel Node via the B-CAN. Warning: Any problems on the C-CAN cause the warning lights for the control units which communicate on this network to light up. The CAN information check is designed precisely for this purpose
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation
Check that the fuel level gauge signal is not in the reserve conditionContinue to Step 1Fuel level gauge in reserve conditionRestore the correct level
1PRELIMINARY CHECKSAll OKProblems metOperation

Connect the Examiner diagnostic equipment and check for the following at the CAN:

  • Node(s) not activated
  • Node(s) faulty
  • Node(s) with CAN error
Continue to Step 6Impossible to converse with the Body ComputerContinue to Step 2
Instrument Panel Node not activated and/or faultyContinue to Step 5
Presence of faults in the CAN networkContinue to Step 9
2CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner, check the possibility of connecting with the Body Computer Node, that there are no errors and that the following parameters are presentContinue to Step 1Impossible to connect with the Body Computer control unitContinue to Step 3
There are errorsContinue according to the instructions for the diagnostic equipment
3ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the electrical power supply for the Body Computer Node is correct and that the wiring between the nodes is correct, in particular that each individual pin is correctly connected See    See E4010 INSTRUMENT PANELContinue to Step 4Positive and/or earth electrical power supply faultyReplace the component involved (if a fuse is involved, search for the cause of the problem)
Electrical connections not workingRestore the correct operation of the wiring
4CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner, check the possibility of connecting with the Body Computer NodeContinue to Step 2Impossible to connect with the Body ComputerReplace the Body Computer Op.    Op. 5505A32 BODY COMPUTER - R R
5CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner check, in the Instrument Panel Node ambient, that there are no errors and the following parameters are present.Continue to Step 8System faultContinue to Step 6
Presence of faults in the CAN networkContinue to Step 9
There are errorsContinue according to the instructions for the diagnostic equipment
6ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the node electrical power supply is correct. Check the wiring between the Body Computer and the Instrument Panel, in particular that each individual pin is correctly connected See    See E4010 INSTRUMENT PANELContinue to Step 7Positive and/or earth electrical power supply faultyReplace the component involved (if a fuse is involved, search for the cause of the problem)
Electrical connections not workingRestore the correct operation of the wiring
7CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner check, in the Instrument Panel Node ambient, that there are no errors and the following parameters are present.Continue to Step 8Fault persistsReplace the instrument panel Op.    Op. 5560B11 ANALOGUE CONTROL PANEL - R+R OR REPLACE
8CHECK WITH ACTIVE DIAGNOSISAll OKProblems metOperation
With the Examiner in the Instrument Panel Node ambient, check, in active diagnosis, that the reserve warning light is correctly activatedContinue to Step 9The reserve warning light does not flashReplace the instrument panel Op.    Op. 5560B11 ANALOGUE CONTROL PANEL - R+R OR REPLACE
9ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the supply / electrical connections of the node(s). Check the (network) wiring between the Engine Management, Body Computer and Instrument Panel, in particular, that each individual pin is correctly connected at each nodeContinue to Step 1Positive and/or earth electrical power supply fault.Replace the component involved (if a fuse is involved, search for the cause of the problem)
Electrical connections not working.Restore the correct operation of the wiring
10CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsContinue to Step 1