How to troubleshooting Turn the ignition switch ON (II). Connect the SCS connector (A) to the power tailgate inspection connector (B). If the ignition switch is turned OFF or SCS connector is disconnected while the safe-diagonals function is working, the safe-diagnosis function stops. If the power tailgate control unit does not memorize DTC, the power tailgate indicator turns on for 3 seconds, then the self-diagnosis is complete.