2398842 - K73 SEAT BELT UNFASTENED WARNING LIGHT ON

The warning light remains on with the driver's seat belt fastened.
The seat belt not fastened warning light is turned on by a command sent via the C-CAN from the Air Bag Node to the Body Computer The latter sends the signal, via the B-CAN, to the Instrument Panel Node.
Results of the tests
1PRELIMINARY CHECKSAll OKProblems metOperation

Connect the EXAMINER diagnostic equipment and check the CAN NETWORK INFORMATION:

  • For inactive control units
  • For control units with errors
  • For control units with CAN errors
Continue to Step 2Presence of faults in the CAN Continue as instructed by the tester
Impossible to converse with the Body ComputerContinue to Step 8
2SWITCH CHECKAll OKProblems metOperation
Check that the seat belt not fastened warning light switch is working properlyContinue to Step 3Switch not working Replace the lower belt branch Op.   7065A14 
3CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Keeping the diagnostic equipment connected, check that there are no CAN errors at the AIR BAG NODEContinue to Step 4Presence of C-CAN faults Continue to Step 11
4CHECK 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 5There are errorsContinue in accordance with the instructions for the diagnostic equipment
5ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the Instrument Panel Node electrical power supply is correct.Continue to Step 6Positive and/or earth electrical power supply fault. Replace the defective component (if a fuse is involved, search for the cause of the problem).
6CHECK ELECTRICAL CONNECTIONSAll OKProblems metOperation
Check the electrical connections between the Body Computer and the Instrument Panel, in particular that each individual pin is correctly connected.Continue to Step 7Electrical connections not working.Restore damaged electrical connection.
7CHECK WITH ACTIVE DIAGNOSISAll OKProblems metOperation
With the Examiner in the Instrument Panel Node ambient, check, in active diagnosis, that the seat belts not fastened warning light is correctly activatedContinue to Step 8The seat belt warning light is not correctly activatedReplace the instrument panel Op. 5560B11
8CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner, check, in the Body Computer Node ambient, that there are no errors and that the seat belt status variesContinue to Step 11Impossible to connect with the Body Computer control unit.Continue to Step 9
Errors present. Continue in accordance with the instructions for the diagnostic equipment.
The parameter values do not changeContinue to Step 11
9ELECTRIC POWER SUPPLY CHECKAll OKProblems metOperation
Check that the Body Computer Node electrical power supply is correct.Continue to Step 10Positive and/or earth electrical power supply fault. Replace the defective component (if a fuse is involved, search for the cause of the problem).
10CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Using the Examiner, check the possibility of connecting with the Body Computer Node. Continue to Step 8Impossible to connect with the Body Computer control unit.Replace the Body Computer Op.   5505A32 
11CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer present End of diagnosisFault persists Replace the Body Computer Op.   5505A32