MERCEDES-BENZ, MERCEDES-MAYBACH · 2025-08-08
Complaint: Red 12 V battery warning message in IC DTC stored in EZS or currently: B161609 No DTC in DC/DC converter DC/DC converter is not providing any output voltage or output current Cause: Due to a reduction in resistance at the HV voltage divider, the DC/DC converter measures an incorrect HV voltage. Regulation of the 12 V output voltage is therefore unstable or turns off. Remedy: Check of the DC/DC converter via XENTRY Diagnosis Actuate BUCK mode for approx. 40 s Normally, the output current will jump up to a high value (e.g. 100 A) and then slowly drop to the current specified value (e.g. 50 A) and then only change slowly and in small increments (video in attachment). In the event of this error cause, the DC/DC converter may react in two possible ways: 1) Despite displayed BUCK…