DTC B1E24: Indirect Light/IG Key Light deactivated (FET failure): Diagnosis

Using scan tool MB991958, read the ETACS-ECU diagnostic trouble code. 

Check if DTC No. B1E23 is set in the ETACS-ECU.

Q: Is the DTC set? 

YES  : Carry out the troubleshooting for DTC No. B1E23. On completion, replace the ETACS-ECU when it has not been replaced as the troubleshooting process for DTC No. B1E23. This is because DTC No. B1E24 cannot be erased.

NO  : Replace the ETACS-ECU.