Technical Service Bulletin LI46.10-P-078012 — 2023 MERCEDES-BENZ EQB 250

Complaint Hand detection system not operating correctly / vehicles with code 266 Fault message in instrument cluster: "Active Emergency Stop Assist not available" "Active Lane Keeping Assist not available" Cause Possible causes: the hand detection mat, the hand detection control unit, the contacts and the steering wheel harness. Remedy Test Procedure: Perform an initial quick test with freeze frame data. Save the N179 - Hand detection system (HE) and N62/4 - Driver assistance system (SG-FAS) control unit logs. Note the fault frequency of fault codes set. Delete the N179 and N62/4 fault memory. Using both hands, "scan" the steering wheel all the way round, including the chrome molding at 6 o'clock (see Picture 1). Read out fault memory and follow steps below for any faults set. Remedy: Vehicles with control unit N179 - Hand detection system (HE): B1E7614: Check contacts and wiring harness in steering wheel by carrying out a visual check for damage, pinched areas, loose connections, etc. (examples in Figs. 2 and 3); If no damage is noted replace the N135 - Steering wheel electronics (LRE) and reassess. If fault code returns replace the steering wheel. Please check the wires and connections in the steering wheel. Afterwards, please check whether the complaint is caused by over torqued screws on steering wheel trim pieces. To do this, please loosen the screws slightly and reevaluate the situation. (Picture 4). P164456: Perform SCN coding. P1CA000: Perform an initial start-up on the N179 hand detection control unit. Faults in N62/4 - Driver assistance system (SG-FAS) control unit with U186B29, U0429E0, U042941, U042929, U042902, U0429E1: If no fault is stored in the N179 control unit: Scan steering wheel as indicated in the test procedure and check whether the fault is reproducible. If no fault code is stored in the hand detection control unit, the fault codes in the driver assistance systems control unit are precautionary messages. Software for the N62/4 - Driver assistance system (SG-FAS) is in preparation to reduce erroneous messages in the driver display.