STEP 3. Check key reminder switch connector C-307, ETACS-ECU connector C-416, rear dome light connector E-04, front dome light connector E-09 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
STEP 6. Using scan tool MB991958, check whether the DTC is set again.
Check again if DTC No.B1E1E is set in the ETACS-ECU.(1) Erase the DTC.
(2) Turn on the dome light.
(3) Check whether DTC No.B1E1E is set.
Is the DTC set?
Go to Step 7. The trouble can be an intermittent malfunction (GROUP 00 - How to use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
STEP 7. Using scan tool MB991958, check whether the DTC is set again.
Check again if DTC No.B1E1E is set in the ETACS-ECU.(1) Erase the DTC.
(2) Disconnect the front dome light connector.
(3) Turn on the dome light.
(4) Check whether DTC No.B1E1E is set.
(5) Repeat steps (1) to (4) for the rear dome light connector to determine a fault cause.
Is the DTC set?
Replace the ETACS-ECU. Replace a defective light (the front dome light body or the rear dome light body).