2398774 - I14 BRAKE LIGHTS AND THIRD BRAKE LIGHT NOT WORKING

The brake lights are activated by the Body Computer Node controlled by the brake switch
Results of the tests
0PRELIMINARY CHECKSAll OKProblems metOperation
Turn the ignition ON and press the brake pedal.Check that the brake lights come on with the brake pedal pressedEnd of diagnosisOne or two of the brake lights do not come onContinue to Step 2
All the brake lights remain offContinue to Step 1
1CHECKING WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the Examiner to the diagnostic socket

Check:

  • that there are no faults in the Body Computer
  • the operation of the brake lights through active diagnosis
Continue to Step 4Body Computer faultyContinue according to the diagnostic equipment instructions
Some of the bulbs do not come onContinue to Step 3
None of the bulbs manages to come onContinue to Step 2
2CHECK ON STOP LIGHTS ELECTRICAL CIRCUITAll OKProblems metOperation

Check, in order:

  • connections between brake pedal and Body Computer;
  • connections between Body Computer and bulbs;
  • bulb earth See   E2021  BRAKE LIGHTS
Continue to Step 3Defective componentReplace the component involved (if a fuse is involved, search for the cause of the problem)
Connections brokenRestore the connections See   E2021  BRAKE LIGHTS
3CHECK ON INDIVIDUAL LIGHTSAll OKProblems metOperation
Check the condition of the individual defective bulbs and the bulb holder assemblyContinue to Step 4Side bulb damagedChange the bulb Op.   5540A50 
Third brake light damagedReplace the bulb Op.   5550D17 
Rear bulb holder assembly faultyReplace the bulb holder assembly Op.   5540A44 
Third brake light faultyReplace the third brake light Op.   5550D16 
4CHECK ON BRAKE PEDAL SWITCHAll OKProblems metOperation
Check that the brake pedal switch is working properlyContinue to Step 5Switch not working properlyReplace the brake pedal switch Op.   5550D10 
5CHECK ON BODY COMPUTER SUPPLYAll OKProblems metOperation
Check that the Body Computer is supplied correctlyContinue to Step 6Incorrect supplyIncorrect supply See   E2021  BRAKE LIGHTS
6CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisFault persistsReplace the Body Computer Op.   5505A32