2398856 - K123 WATER IN DIESEL FILTER WARNING LIGHT ON CONSTANTLY

The Engine Management Node sends the message via the C-CAN to the Body Computer which makes it available, via the B-CAN, to the Instrument Panel Node.
Any faults in the C-CAN light up the control unit warning lights which communicate on this network. The CAN information check is designed precisely for this purpose
Results of the tests
1PRELIMINARY CHECKSAll OKProblems metOperation

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

  • 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 faulty Continue to Step 5
Engine Managment node not activated and/or faultyContinue to Step 9
Presence of faults in the CAN Continue to Step 13
2CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner check, the possibility of connecting with the Body Computer Node and that there are no errors and the following parameters are present.Continue to Step 1Impossible to connect with the Body Computer control unitContinue to Step 3
There are errorsContinue to Step 6
3ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the electrical supply for the Body Computer Node is correct and check the wiring between the nodes, in particular that each individual pin is correctly connectedContinue 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.   5505A32 
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 presentContinue to Step 8System faulty Continue to Step 6
Presence of faults in the CAN Continue to Step 13
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 Continue 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 presentContinue to Step 8Fault persists Replace the instrument panel Op. 5560B11
8CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
With the Examiner in the Instrument Panel Node ambient, check, in active diagnosis, that the warning light in question is correctly activated Continue to Step 9The warning light in question does not flash Replace the instrument panel Op. 5560B11
9CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation

Keeping the diagnostic equipment connected, check for the following at the Engine Management Node:

  • System/component faults
  • CAN faults
Continue to Step 12System/component faultsContinue to Step 10
Presence of faults in the CAN Continue to Step 13
There are errorsContinue as instructed by the tester
10ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the node electrical power supply is correct Check the wiring between the Body Computer and the NCM, in particular that each individual pin is correctly connectedContinue to Step 11Positive 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
11CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner check, in the Engine Management Node ambient, that there are no errors and the following parameters are presentContinue to Step 9Fault persistsReplace the Engine Management Node Op.   1060G80 
12CHECK WITH ACTIVE DIAGNOSISAll OKProblems metOperation
Using the Examiner in the Engine Management Node ambient, check, in active diagnosis, that the water presence warning light is correctly activated.Continue to Step 6The warning light does not flash Replace the Engine Management Node Op.   1060G80 
13ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the supply / electrical connection(s) for the node(s) is correct. Check the (network) wiring between the Engine Management, Body Computer and Instrument Panel, in particular that each individual pin is correctly connected at each node Continue to Step 1Positive 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 damaged wiring
14CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persists Continue to Step 1