184000451 - I20 FOG LIGHTS NOT WORKING

When the front fog lamps switch is operated with the side lights on, the front fog lamps do not work.
Results of the tests
1CHECK ON FRONT FOG LIGHT RELAY (POWER CIRCUIT)All OKProblems metOperation
On the engine compartment control unit, swap the front fog light relay with the horn relay (it is the third on the same row), and check that the front fog light works properly after the swap.Continue to Step 2Even after the swap, the front fog lights still do not workContinue to Step 3
2REPLACING HORN RELAY (POWER CIRCUIT)All OKProblems metOperation
Replace the horn relay (which was previously the front fog light relay) and check that they are working properlyEnd of diagnosis.
3CHECKING FRONT FOG LIGHT RELAY SUPPLY (POWER CIRCUIT)All OKProblems metOperation
Refit the two relays in their original positions.With the ignition on, check that the front fog light is correctly supplied by the battery.Then connect to the relay supply from the Body Computer and check that when the front fog lights are switched on, the supply is sent to the relay.Also check that the electrical connections between the Body Computer, battery and relay are not faulty See E2030 FOG LIGHTS
Do not connect the relay
Continue to Step 4No supply from batteryRestore the correct supply to the relay. If necessary replace the faulty components (if a fuse is involved, search for the cause of the problem)
Supply enablement not provided by the Body ComputerContinue to Step 6
Connections faultyRestore the correct connections See E2030 FOG LIGHTS
4CHECKING WITH DIAGNOSTIC EQUIPMENTAll OKProblems metOperation
Connect the Examiner to the diagnostic socket.Check that there are no faults in the Body ComputerCheck light operation while in active diagnosis mode.Continue to Step 5Fog lamp relay errorContinue to Step 6
Lights not activatedContinue to Step 5
5CHECK ON INDIVIDUAL LIGHTSAll OKProblems metOperation
Check the condition of individual bulbs and lampsContinue to Step 6Bulb damagedChange the bulb Op. 5540B22
Left light cluster faultyRepair or change the light unit Op. 5540B78
Right light cluster faultyRepair or change the light unit Op. 5540B79
6CHECK FOG LAMP ELECTRIC CIRCUITAll OKProblems metOperation

Check, in order:

  • front fog lamp fuse;
  • connections between Body Computer and engine bay control unit;
  • connections between engine bay control unit and bulbs;
  • connections between Body Computer and fog lights switch;
  • bulb earth See E2030 FOG LIGHTS
Continue to Step 7Defective componentReplace the component involved (if a fuse is involved, search for the cause of the problem)
Connections brokenRestore the connections See E2030 FOG LIGHTS
7CHECK ON FRONT FOG LAMPS SWITCHAll OKProblems metOperation
Check the operation of the fog lights switch See E2030 FOG LIGHTS Continue to Step 8Fog lights switch faultyReplace the control panel Op. 7040A56
8CHECK ON CORRECT OPERATIONAll OKProblems metOperation
Check that the fault is no longer presentEnd of diagnosisThe fault persistsReplace the Body Computer Op. 5505A32