125000538 - 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
1CHECK 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 instructions for the diagnostic equipment
Some of the bulbs do not come onContinue to Step 3
None of the bulbs manages to come onContinue to Step 2
2BRAKE LIGHTS ELECTRICAL CIRCUIT CHECKAll OKProblems metOperation

Check, in order:

  • connections between brake pedal and Body Computer;
  • connections between Body Computer and bulbs
  • bulb earth See    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    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.    Op. 5540A50 TAIL-LIGHT BULB (ONE), LH OR RH - REPLACE
Third brake light damagedChange the bulb Op.    Op. 5550D17 THIRD BRAKE LIGHT - R R
Right rear bulb holder assembly faultyReplace the bulb holder assembly Op.    Op. 5540A62 RIGHT OUTSIDE REAR LIGHT CLUSTER - R.R.
Left rear bulb holder assembly faultyReplace the bulb holder assembly Op.    Op. 5540A60 LEFT OUTSIDE REAR LIGHT CLUSTER - R.R.
Third brake light faultyReplace the third brake light Op.    Op. 5550D16 THIRD STOP LIGHT - R+R
4BRAKE PEDAL SWITCH CHECKAll 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 supplyRestore the correct supply See    See E2021 BRAKE LIGHTS
6CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsReplace the Body Computer Op.    Op. 5505A32 BODY COMPUTER - R R