What 21 owners told NHTSA about the 2014 Mercedes-benz B-class E-cell

VEHICLE BATTERY WARNING LIGHT CAME ON INSTRUCTING TO STOP DRIVING VEHICLE IMMEDIATELY. LIKE SO MANY OTHER OWNERS WHO HAVE FILED COMPLAINTS, MERCEDES DEALER-MECHANIC SAID THAT COOLANT HAD GOTTEN INTO BATTERY AND DRIVE UNIT NEEDS TO BE REPLACED. ESTIMATED COST $12,000 - RENDERING CAR TOTALLED. INDEPENDENT EV SPECIALIST HAS PRESSURE TESTED COOLING SYSTEM AND FINDS NO LEAKS. FORTUNATELY, I WAS IN A SAFE PLACE AT THE TIME I NEEDED TO STOP THE CAR. IF I HAD BEEN OUT ON THE FREEWAY DURING HEAVY TRAFFIC OR AT NIGHT, THIS WOULD HAVE BEEN UNSAFE. IF THERE ARE PROBLEMS WITH THE COOLANT AND DRIVE UNIT, IT LEADS ME TO BELIEVE THAT PROBLEM COULD LEAD TO FIRE, IF NOT POTENTIAL CRASH IF DRIVER LOSES POWER IN CONGESTED TRAFFIC AT HIGH SPEED. AS AN ALL ELECTRIC CAR, BRAKES AND TRANSMISSION RELY ON POWER TO SAFELY BRING CAR TO A STOP.

NHTSA ODI 11281161

THIS IS AN ELECTRIC VEHICLE. WHEN SLOWING DOWN THE PADDLE SHIFTERS CAN BE USED TO PUT THE CAR IN 'D-' MODE, FOR MORE AGGRESSIVE ENGINE BRAKING. THIS INCREASES THE RATE OF DECL WITHOUT USING THE MECHANICAL BRAKES. THIS HAS WORKED WELL FOR FOUR YEARS AND 65,000 MILES. TODAY THERE WAS A 'ONE TIME' MALFUNCTION. I DID THE USUAL 'D-' 'DOWN SHIFT' TO SLOWDOWN FROM 30 MPH, IN TRAFFIC, FOR RED LIGHT. THE CAR DID NOT AGGRESSIVELY SLOW DOWN AND I APPLIED THE BRAKES. I NOTICED THE CAR NEED EXCESSIVE BREAK PEDAL PRESSURE TO MAKE WHAT SHOULD BE A NORMAL STOP. I GLANCED DOWN AT THE POWER METER AND IT IS INDICATING POWER IS STILL BEING APPLIED TO THE MOTOR. THE INDICATOR WAS HALF WAY TO THE FIRST TIC AND DROPPING AS I SLOW DOWN. THIS IS ABOUT 25 AMPS POWERING THE MOTOR, NOT RECHARGING THE BATTERY. THIS AGGRESSIVE BRAKING INCIDENT IS NOT RELATED TO COLD THE WEATHER BATTERY PROTECTION MODE WHERE ENGINE BREAKING IS DISABLED UNTIL THE BATTERY REACHES MINIMUM OPERATING TEMPERATURE. THE OUTSIDE AIR TEMPERATURE WAS 40F. TO RECAP, WHILE APPLYING THE MECHANICAL BRAKES, THE ELECTRIC MOTOR WAS STILL PRODUCING POWER AS INDICATED BY THE AMMETER, STOPPING THE CAR REQUIRED MORE THAN THE USUAL AMOUNT OF BRAKE PRESSURE.

NHTSA ODI 11182457

EXTREMELY DANGEROUS SUDDEN LOSS OF POWER WHILE DRIVING 70+ MPH ON BUSY HIGHWAY. WAS ALMOST INVOLVED IN A SERIOUS TRAFFIC COLLISION BECAUSE IT A STOPPED IN THE ROAD. ATTEMPTS TO RESTART THE VEHICLE FAILED. COULD NOT GET THE VEHICLE OUT OF "PARK" AND WAS UNABLE TO SWITCH IT INTO "NEUTRAL" TO ROLL THE VEHICLE OUT OF THE LANE OF HIGH SPEED TRAFFIC. THE INABILITY TO GET THE VEHICLE INTO "NEUTRAL" FURTHER COMPROMISED MY SAFETY AND THE SAFETY OF OTHER DRIVERS ON THE HIGHWAY. MAIN LOW VOLTAGE 12V BATTERY DIED SOON AFTER INCIDENT AND CREATED AN ISSUE FOR TOW TRUCK OPERATOR. HE HAD A LOT OF TROUBLE GETTING IT INTO NEUTRAL BECAUSE THERE SEEMS TO BE NO STANDARDIZED MANUAL / MECHANICAL METHOD TO RELEASE THE PARKING PRAWL IN THE TRANSMISSION UNLESS THE LOW VOLTAGE 12V SYSTEM IS FULLY FUNCTIONING. PERHAPS THEY NEED TO REPLACE THE ENTIRE DRIVETRAIN UNIT LIKE TESLA HAS DONE OR THEIR CUSTOMERS. ELECTRIC POWERTRAIN UNIT USED IN THE MERCEDES IS IDENTICAL TO EARLY TESLA VEHICLES. TELSA REDESIGNED AND UPDATED THESE POWERTRAIN UNITS WITH FREE REPLACEMENTS THAT RESOLVE THIS ISSUE COMPLETELY. MERCEDES NEEDS TO DO THE SAME REPAIR FOR CUSTOMERS AS TESLA DID. SOFTWARE UPDATE IS OBVIOUSLY NOT A SUFFICIENT FIX FOR THIS ISSUE, THERE MUST BE PHYSICAL FAULTS AS WELL. ANOTHER ISSUE IS A MYSTERY CLUNK THAT YOU CAN FEEL THRU THE ACCELERATOR PEDAL WHEN STARTING FROM A COMPLETE STOP. SEVERAL ATTEMPTS TO GET SERVICE TECHS TO FIX THIS BUT THEY HAVE BEEN UNABLE TO FIX IT. PERHAPS IT IS RELATED TO THE WELL KNOWN EARLY PRODUCTION TESLA DRIVETRAIN DEFECTS. MY VEHICLE CURRENTLY HAS 43,276 MILES. THIS VEHICLE ALREADY HAD THE SOFTWARE UPDATE THAT WAS SUPPOSED TO GUARANTEE THAT THE SUDDEN LOSS OF POWER WOULD NOT HAPPEN AGAIN. (( NHTSA CAMPAIGN NUMBER: 15V655000 )) I HOPE MERCEDES STEPS UP TO SOLVE THIS ISSUE LIKE TELSA HAS DONE FOR THEIR CUSTOMERS.

NHTSA ODI 10906967