Total Complaints
17 filings
MERCEDES-BENZ 420 · model year
17 NHTSA complaints, 2 crash reports for this specific cohort.
NHTSA overall rating
Not crash-tested
New Car Assessment Program
The 1994MERCEDES-BENZ420 carries 17 consumer safety complaints in NHTSA's Office of Defects Investigation database for this specific model-year cohort. Within that volume, owners reported 2 crashes, 0 fires, 0 injuries, and 0 fatalities. No NCAP 5-star crash-test rating is available for this model year in the federal database.
Component-level analysis is where model-year complaints become actionable: the top complaint category for the 1994 420 is child seat:shell:booster with 3 filings, followed by service brakes, hydraulic:antilock/traction control/electronic limited slip (2) and electrical system:wiring (2). Concentration in one or two component groups is the classic signature of a systemic defect; a flat distribution usually reflects normal aging, warranty complaints, or isolated build-plant variability.
NHTSA currently has 15 investigation files overlapping the 1994 420. Owners comparing this cohort against neighboring years should pair the counters above with the complaint-by-year trend on the parent model page — a spike in a single year often tracks to a platform refresh, a new transmission supplier, or an updated ECU calibration. Use the related-complaint feed below to read raw owner narratives before deciding whether any pattern here affects your specific use case.
Total Complaints
17 filings
Crashes Reported
2 reports
Source
NHTSA ODI
Federal complaints database
At or below the fleet median complaint volume.
| Component | Count |
|---|---|
| CHILD SEAT:SHELL:BOOSTER | 3 |
| SERVICE BRAKES, HYDRAULIC:ANTILOCK/TRACTION CONTROL/ELECTRONIC LIMITED SLIP | 2 |
| ELECTRICAL SYSTEM:WIRING | 2 |
| ELECTRICAL SYSTEM | 2 |
| SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS:DISC:PADS | 1 |
| AIR BAGS:FRONTAL | 1 |
| SEATS:FRONT ASSEMBLY:RECLINER | 1 |
| VEHICLE SPEED CONTROL | 1 |
| SERVICE BRAKES, HYDRAULIC:FOUNDATION COMPONENTS | 1 |
| UNKNOWN OR OTHER | 1 |
| ENGINE AND ENGINE COOLING | 1 |
| ELECTRICAL SYSTEM:WIRING:FRONT UNDERHOOD | 1 |
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
Mileage: 170,000
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
Mileage: 90,000
VEHICLE IS RUNNING ERRATICALLY. UPON INVESTIGATION, I FOUND THAT THE ENGINE WIRING HARNESS IN MODEL YEARS INCLUDING MY 1994 MERCEDES BENZ E420 HAVE A CHRONIC PROBLEM WITH DETERIORATING INSULATION. AS SOME FIRES AND CRASHES HAVE BEEN REPORTED, I AM PAYING TO HAVE THIS PART REPLACED. *TR
Mileage: 139,595
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
Mileage: 65,000
VEHICLE CHECKED AND FOUND THAT INSULATION ON ALL OF THE FUEL INJECTION WIRING, TEMPERATURE SENSOR AND FAN THERMAL SWITCH HARNESS DETERIORATED CAUSING WIRES TO RUB TOGETHER. CONSUMER DISCOVERED THAT HARNESS INSULATION IS MADE OF VERY POOR MATERIAL. THE INSULATION BREAKS VERY EASY AT THE TOUCH AND TURNS INTO DUST. THE WHOLE WIRE HARNESS IS IN THE SAME SITUATION THIS IS A MAJOR SAFETY ISSUE CAN STALL OR SHUT OFF WHILE DRIVING AT HIGH SPEED. REPLACE OF WIRE HARNESS AT A COST OF$1500 WAS NEEDED TO FIX. *JB
Mileage: 117,000
5/18/2006. CHECK ENGINE LIGHT APPEARED. TOOK VEHICLE TO MBZ REPAIR SHOP AND FOUND THE ENGINE WIRING HARNESS'S WIRE INSULATION BREAKING APART AND EXPOSING THE BARE WIRING. COST OF REPAIR +$900.00. *JB
THE VEHICLES ASR LIGHT ILLUMINATED THEN THE POWER DRIVE WOULD SHUT OFF. *NLM *TS
Mileage: 103,250
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
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 W
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
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
THERE IS NO WAY TO SAFELY INSTALL A CHILD SEAT ON THIS YEAR MODEL WITH THE SUPPLIED SEAT BELTS
COMPLETE LOSS OF BRAKING ON TWO OCCASIONS WHILE DRIVING AT LESS THAN 5 MILES, VEHICLE IS ABS SYSTEM. TT
AIRBAG DID NOT DEPLOY WHILE INVOLVED IN AN ACCIDENT AT 30 MPH. TT
FRONT BRAKE PADS SQUEAK, CAUSING ANTI-LOCK BRAKE SYSTEM TO ACTIVATE. *SKD
Data as of 2025. Sources: NHTSA Office of Defects Investigation (ODI) complaints database, NHTSA recall campaign API, NHTSA NCAP crash-test ratings, and NHTSA FARS for fatality cross-reference.
Read our methodology — how this data is sourced, computed, and verified.