312000602 - J021 HEATED REAR WINDSCREEN NOT WORKING

With the ignition ON, when the button in the auxiliary control panel on the dashboard is pressed, the heated rear windscreen does not heat up properly
If the battery voltage is below 11.6 V, the heated rear windscreen and rear view mirrors are not supplied by the control unit
Test results
0PRELIMINARY CHECKSAll OKProblems encounteredOperation
Check that the rear view mirrors heat up properly when the button in the climate control system control panel is pressed.Move on to Step 1The rear view mirrors do not heat up properlyProceed as instructed in the    See table J022 DOOR MIRROR DEFROSTING NOT WORKING
1HEATED REAR WINDSCREEN RELAY CHECKAll OKProblems encounteredOperation
Check the condition of heated rear windscreen relay T19 (located in the engine compartment control unit)Move on to Step 2Relay T19 faulty.Replace relay T19.
2ENGINE COMPARTMENT CONTROL UNIT FUSE OPERATION CHECKAll OKProblems encounteredOperation
Check that fuse F20 in the engine compartment control unit is working properly.Move on to Step 3Fuse blown.Replace the fuse and find out what caused the malfunction.
3CHECK USING DIAGNOSTIC EQUIPMENTAll OKProblems encounteredOperation
Keeping the diagnostic equipment connected, go into active diagnosis and check that the rear windscreen is working properly; to carry out the test, disconnect the rear windscreen connector and insert a bulb and check that it lights up.Move on to Step 5Bulb does not light up.Move on to Step 4.
4HEATED REAR WINDSCREEN POWER SUPPLY CHECKAll OKProblems encounteredOperation
Check the following, in order:

  • Connection to earth of the heated rear windscreen;
  • Heated rear windscreen power supply line
    See E3030 DEFROSTING REARSCREEN AND REAR VIEW MIRRORS
Move on to Step 5Connection broken.Restore the correct connections.
5HEATED REAR WINDSCREEN FILAMENTS CHECKAll OKProblems encounteredOperation
Check the condition of the heated rear windscreen filaments.End of diagnosisFilaments broken.Replace the heated rear windscreen    Op. 7035B14 REAR WINDOW GLASS - R.R INCLUDES CLEANING HOUSING