1994 Mercedes-Benz 420 Problems
Owner-reported complaints filed with NHTSA, grouped by component
Data refreshed
What this page shows
Everything below is an owner-reported complaint submitted to NHTSA about the 1994 Mercedes-Benz 420, grouped by the component NHTSA recorded on the report. These are not confirmed defects, and they are not recalls. NHTSA does not verify most reports before publishing them, and a category with more reports in it is not evidence that a part is defective.
Complaints are reports submitted by owners and drivers to NHTSA. They are not verified and do not establish that a defect exists.
Reports by component
Ranked by how many owner reports name each component category
- Electrical531.3%
- Brakes425.0%
- Seat belts318.8%
- Driver assistance16.3%
- Airbags16.3%
- Engine16.3%
- Interior & seats16.3%
Percentages are of component mentions. A single complaint can name more than one component, so these do not sum to the total complaint count.
Each component in detail
What the reports in each category say, in the owners' own words
Electrical
Reports naming the electrical system — wiring, battery, charging, control modules, infotainment and electrical accessories.
From owner reports, verbatim
CAR STOPPED SHIFTING, CHECK ENGINE LIGHT AND ASR LIGHT APPEARED WHILE DRIVING. TOOK CAR INTO AUTO MECHANIC AND WAS TOLD WIRING HARNESS WOULD NEED TO BE TOTALLY REPLACED AND WOULD COST MORE THAN AUTO'S WORTH. SAID THESE CARS WERE NOTORIOUS FOR HAVING WIRING HARNESS PROBLEMS AND CAN NOT BELIEVE IT HAS NOT CAUGHT ON FIRE YET. *TR
I OWN A 1994 S 420 MERCEDES-BENZ I AM VERY CONCERNED FOR MY CHILD'S SAFETY AND MY OWN SAFETY AS WELL. THE WIRING HARNESS IS SHORTING OUT EVERYWHERE... SHAME ON MERCEDES-BENZ OF AMERICA..THEY KNOW ABOUT THIS DANGER AND JUST IGNORE THE WHOLE THING.. I'VE RESEARCHED IT REALLY WELL AND THE SAME PROBLEM OCCURS OVER AND OVER WITH ALL CARS OF THIS VINTAGE..I WONDER HOW MANY PEOPLE WILL HAVE TO DIE BEFORE THEY RECALL ON THIS DANGEROUS SITUATION???THEY SHOULD STAND UP TO THE PLATE.. THE HARNESS IS 7-8 HUNDRED DOLLARS.. COME ON GUYS!!! HOW MUCH DO YOU THINK YOUR LIFE IS WORTH?? THAT'S RIGHT, ALOT MORE THAN THAT.. LETS FIX THE PROBLEM BEFORE SOMEONE DIES... OR MANY DIE... *TR
Too few reports in this category for a page of its own — they appear in the full complaint list.
Brakes
Reports naming service brakes, the antilock braking system, brake hoses, master cylinders or the parking brake.
From owner reports, verbatim
AFTER COMING TO A COMPLETE STOP VEHICLE WILL TRY TO SURGE FORWARD WHILE CONSUMER APPLIES BRAKES. THIS HAS BEEN AN INTERMITTENT PROBLEM. CONTACTED DEALER, AND DEALER CANNOT FIND CAUSE. HAS REPLACED SEVERAL BRAKE PARTS BUT FOUND NOTHING.*AK. CONSUMER STATED INCIDENT HAPPENS WHEN THE VEHICLE HAS BEEN DRIVEN FOR AN HOUR OR MORE, THERE IS USUALLY A SOUND, CONSUMER ALSO STATED ALL 4 ROTORS HAVE BEEN REPLACED.*JB
THE PROBLEM STARTED LAST AUGUST. IT OCCURRS ONLY OCCASIONALLY AND HAS NEVER BEEN DUPLICATED WHEN AT A DEALERSHIP OR REPAIR SHOP. AFTER APPLYING THE BRAKES AND COMING TO A STOP, THE CAR STARTS TO ROLL FORWARD. WHEN I TAKE MY FOOT OF THE BRAKE PEDAL AND REAPPLY IT, THE CAR THEN STOPS. HOWEVER, ON APRIL 7TH WHEN THIS OCCURRED REAPPLYING THE BRAKE DID NOT STOP THE CAR AND I ROLLED INTO THE REAR END OF A TRATOR TRAILER TRUCK WHO WAS STOPPED AT A RED LIGHT. IN NOVEMBER 2001 I TOOK THE CAR TO THE MERCEDES DEALERSHIP IN HAVERHILL, MA SMITH MOTORS. THEY PUT IN A NEW MASTER CYCLINDER. ON DECEMBER 24TH I EXPERIENCED THE SAME PROBLEM. SMITH MOTORS SAW THE CAR ON JAN 2, 2002 AND SAID UNTIL NEW ROTORS WERE PUT IN THEY COULD NOT DIAGNOSE THE PROBLEM. IN FEB I WAS IN DEVON, PA AND STOPPED IN THE MERCEDES DEALERAHIP THERE. THEY SAID WHEN A CUSTOMER EXPERIENCES THE PROBLEM I WAS HAVING THEY PUT IN NEW BRAKE SENSORS. (SEVERAL REPAIR SHOPS INCLUDING THE DEVON DEALERSHIP TOLD ME THINNING ROTORS WOULD NOT CAUSE THIS PROBLEM.) I HAD NEW ROTORS PUT IN, BUT EXPPERIENCED THE PROBLEM ON APRIL 7TH. THE CAR WAS TOWED BACK TO SMITH MOTORS AND THE REGIONAL MERCEDES REPAIR EXPERT EXAMED AND TESTED THE BRAKE SYSTEM FOR 3 HOURS AND SAID THERE WAS NO PROBLEM EXCEPT I NEEDED NEW ROTORS. THEY TOLD MY INSURANCE COMPANY EITHER I DIDN'T HAVE MY FOOT ON THE BRAKE OR THAT THE CAR IS OLD! I HAVE HAD NEW ROTORS PUT IN THE CAR BUT AM TERRIFIED OF DRIVING IT. PLEASE ADVISE. I CHECKED MY VIN NUMBER USING MY REGISTRATION.*AK
Too few reports in this category for a page of its own — they appear in the full complaint list.
Seat belts
Reports naming seat belts, buckles, retractors and pretensioners.
From owner reports, verbatim
REFER ODI:479198 THERE IS NO WAY TO SAFELY SECURE A CHILD SEAT IN THIS YEAR AND MODEL. *AK
REFER TO NHTSA OFFICE OF DEFECTS INVEST. ODI ID: 479198 CAR SEAT PROBLEM STILL EXIST
Too few reports in this category for a page of its own — they appear in the full complaint list.
Driver assistance
Reports naming forward-collision avoidance, lane keeping, back-over prevention, cruise control and related electronic driver-assistance systems.
From owner reports, verbatim
AFTER COMING TO A COMPLETE STOP VEHICLE WILL TRY TO SURGE FORWARD WHILE CONSUMER APPLIES BRAKES. THIS HAS BEEN AN INTERMITTENT PROBLEM. CONTACTED DEALER, AND DEALER CANNOT FIND CAUSE. HAS REPLACED SEVERAL BRAKE PARTS BUT FOUND NOTHING.*AK. CONSUMER STATED INCIDENT HAPPENS WHEN THE VEHICLE HAS BEEN DRIVEN FOR AN HOUR OR MORE, THERE IS USUALLY A SOUND, CONSUMER ALSO STATED ALL 4 ROTORS HAVE BEEN REPLACED.*JB
Too few reports in this category for a page of its own — they appear in the full complaint list.
Airbags
Reports naming the air-bag system — deployment behaviour, inflators, sensors and warning lights.
From owner reports, verbatim
AIRBAG DID NOT DEPLOY WHILE INVOLVED IN AN ACCIDENT AT 30 MPH. TT
Too few reports in this category for a page of its own — they appear in the full complaint list.
Engine
Reports naming the engine itself — including stalling, misfires, oil consumption, cooling and internal engine components.
From owner reports, verbatim
I GOT 94 E420 BENZ WITH DEFECT ENGINE WIRING HARNESS. THEY ARE CRACKING. THE IDLE IS ROUGH AND I GOT ENGINE CODE ERRORS. ONE TIME THE ENGINE FAILED ON THE SURFACE STREET. IT WAS LUCKY THERE WAS NO CAR BEHIND ME AT THAT TIME. MY MECHANIC TOLD ME THAT ALL MERCEDES MODELS FROM 91-96 HAVE THIS PROBLEM. THAT WAS SO SAD THAT NO ONE HAS TAKEN ACTION AGAINST THE FACTORY. *TR
Too few reports in this category for a page of its own — they appear in the full complaint list.
Interior & seats
Reports naming seats, latches, locks, linkages and interior fittings.
From owner reports, verbatim
DRIVING IN LOCAL TRAFFIC 40 MPH THE SEATS STARTED TO RECLINE ALL THE WAY TO THE PASSENGER BACK SEAT. TRIED TO USE THE SEAT RECLINER BUTTON, BUT IT FAILED. IT WILL NOT READJUST BY ITSELF. CONTACTED DEALER. *AK
Too few reports in this category for a page of its own — they appear in the full complaint list.
Higher-selling and older vehicles accumulate more reports. Counts are not failure rates and are not directly comparable between vehicles that sold in very different numbers.
Elsewhere on this vehicle
Data sources
- NHTSA Office of Defects Investigation — owner-reported complaints and the components recorded on them
Data on this page last refreshed .