2751091 - K64 AIRBAG FAILURE WARNING LIGHT ON

The brake fluid warning light remains on with the handbrake not applied.
The brake fluid level signal is sent by the special sensor (N.C. with maximum brake fluid level) to the Body Computer Node which makes it available via the B-CAN to the Instrument Panel Node which lights up the dedicated warning light and displays the insufficient brake fluid level message; if the warning light is faulty the relevant message is displayed.
Results of the tests
1PRELIMINARY CHECKAll OKProblems metOperation
Check that the brake fluid/VDC level warning light failure message is not present. Check that the insufficient brake fluid level message is not presentContinue to Step 6Warning light failure message present Continue to Step 7
Insufficient brake fluid message presentContinue to Step 2
2TOP UP BRAKE FLUID LEVELAll OKProblems metOperation
Top up the brake fluid level and check that the warning light and the message are not longer present Continue to Step 9The warning light does not go off Continue to Step 3
3CHECKING ELECTRICAL EQUIPMENTAll OKProblems metOperation
Disconnect the connector from the fluid level sensor and, using a multimeter, check the efficiency of the connection to earth See   E4010  INSTRUMENT PANEL Continue to Step 4Faulty earthRestore earth connection efficiency See   E4010  INSTRUMENT PANEL Continue to Step 3
4CHECKING ELECTRICAL EQUIPMENTAll OKProblems metOperation
Bridge the cables at the connector and check that the warning light in the instrument panel is not on and the message is no longer present See   E4010  INSTRUMENT PANEL Continue to Step 9Warning light on and message presentContinue to Step 5
5CHECKING ELECTRICAL EQUIPMENTAll OKProblems metOperation
Check the continuity of the cable from the connector to the Body computer See   E4010  INSTRUMENT PANEL Continue to Step 7Cable brokenRestore connection See   E4010  INSTRUMENT PANEL
6CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the Examiner and check the plausibility, at the Body Computer Node, of the handbrake applied parameterContinue to Step 7The parameter is not plausibleContinue according to the instructions See table   K69 
7CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the Examiner or keep it connected and check the operation of the brake fluid level warning light at the Instrument Panel Node through active diagnosisContinue to Step 8The warning light is damaged / not flashing Replace instrument panel Op. 5560B11
8CHECK WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Keeping the Examiner connected, check the plausibility of the brake fluid level parameter at the Body Computer NodeContinue to Step 9The parameter is not plausibleReplace the Body Computer Op.   5505A32 
9CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer present End of diagnosisThe fault persistsReplace the brake fluid reservoir and sensor.