23 · Diagnostics

Brake lights and third brake light not working

Fault diagnosisBrake lights and third brake light not working

BRAKE LIGHTS AND THIRD BRAKE LIGHT NOT WORKING

The side brake lights and the third brake light are activated by the Body Computer Node controlled by the brake light switch.

1	CHECK USING DIAGNOSTIC EQUIPMENT	All OK	Problems encountered	Operation
	Connect an Examiner tester and ensure that the following errors are not present in the Body Computer node	Move on to Step 2	Errors present in the Body Computer Node	Proceed as instructed by the diagnostic tester
2	BRAKE LIGHT OPERATION CHECK.	All OK	Problems encountered	Operation
	Keep the diagnostic tester connected and check that the brake lights are operating correctly in active diagnosis mode	Move on to Step 3	Bulbs not operating	Replace the bulb or the associated wiring
3	ELECTRICAL SYSTEM CHECK	All OK	Problems encountered	Operation
	Check the continuity of the bulb wiring See E2021 BRAKE LIGHTS	Move on to Step 4	Wiring broken	Restore correct wiring
4	CONTROL SWITCH CHECK	All OK	Problems encountered	Operation
	Check that the brake switch is working properly by conducting See Test 5550DA BRAKE PEDAL SWITCH OPERATION CHECK	Move on to Step 5	Brake pedal switch faulty	Replace the brake pedal switch [PR_5550D10] Op. 5550D10 BRAKE LIGHT SWITCH - R+R
5	BODY COMPUTER CONNECTION CHECK	All OK	Problems encountered	Operation
	Check for deformed terminals or connections not present on the Body Computer	Move on to Step 6	Missing connections/pins bent	Renew the correct connections
6	CHECK ON CORRECT OPERATION	All OK	Problems encountered	Operation
	Check that the fault is no longer present	End of diagnosis	The fault persists	Replace Body Computer Op. 5505A32 BODY COMPUTER - R.R

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