This bulletin applies to 2016-2020 Mercedes-Benz Model 205 Hybrid, Model 253 Hybrid, Model 222 Hybrid and Model 242 EV vehicles equipped with an auxiliary supplemental heater. A high-voltage battery warning message may appear in the instrument cluster. A possible no-start condition may be found and/or the vehicle charging may be interrupted or inhibited.
Moisture and/or corrosion may be present in the high voltage PTC heater booster female connector (N33/5 female connector 1). Inspect the 12V female connector for a damaged main silicone seal, missing blind plugs, damaged individual conductor seals and foreign object contamination. Replace the high voltage PTC heater booster. The wiring harness can be repaired if necessary.
DTC codes may appear as follows:
P0A0BOO (interlock circuit of the high voltage on-board electrical system malfunction)
B10BE00 (switchover valve on PTC heater booster high voltage has a malfunction)
P0A0A00 (interlock circuit of the high voltage system has an electrical fault)
P0A0D00 (interlock circuit has a short circuit to positive)
B19A400 (LIN bus 2 of the A/C system has a malfunction)
P142600 (There is a vehicle-side isolation fault in the high voltage system)