STEP 1. Check ETACS-ECU connector C-415, sunshade illumination (RH) connector E-10, sunshade illumination (LH) connector E-13 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
STEP 4. Using scan tool MB991958, check whether the DTC is set again.
Check again if DTC No.B1E23 is set in the ETACS-ECU.(1) Erase the DTC.
(2) Turn on the sunshade illumination.
(3) Check if DTC No.B1E23 is set.
Is the DTC set?
Go to Step 5. The trouble can be an intermittent malfunction (GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
STEP 5. Using scan tool MB991958, check whether the DTC is set again.
Check again if DTC No.B1E23 is set in the ETACS-ECU.(1) Erase the DTC.
(2) Disconnect the sunshade illumination connector.
(3) Turn on the sunshade illumination.
(4) Check if DTC No.B1E23 is set.
Is the DTC set?
Replace the ETACS-ECU. Replace the spot light assembly.