NHTSA owner reports · September 18, 2026 snapshot.
What owners actually said
88 reportsMileage unknown · Apr 3, 2012
Service Brakes, Hydraulic
I RECENTLY TOOK MY 2002 ML320 INTO MY LOCAL MERCEDES REPAIR SHOP (FAIRFIELD, CT) TO HAVE SOME WORK DONE. WHEN I COLLECTED THE VEHICLE AND AS I WAS LEAVING, THE ESP/BAS, ETS AND ABS LIGHTS CAME ON SIMULTANEOUSLY. THIS HAD HAPPENED ON MANY PREVIOUS OCCASIONS OVER THE YEARS AND EVERY TIME I HAD MENTIONED IT TO THE MERCEDES SERVIC…
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I RECENTLY TOOK MY 2002 ML320 INTO MY LOCAL MERCEDES REPAIR SHOP (FAIRFIELD, CT) TO HAVE SOME WORK DONE. WHEN I COLLECTED THE VEHICLE AND AS I WAS LEAVING, THE ESP/BAS, ETS AND ABS LIGHTS CAME ON SIMULTANEOUSLY. THIS HAD HAPPENED ON MANY PREVIOUS OCCASIONS OVER THE YEARS AND EVERY TIME I HAD MENTIONED IT TO THE MERCEDES SERVICE PEOPLE THEY HAVE SAID THAT THIS IS A COMMON FAULT AND THAT I SHOULD TURN OFF THE ENGINE, WAIT AND THEN RE-START AND THIS SHOULD CLEAR THE ISSUE. THIS HAD MOSTLY WORKED UNTIL THIS RECENT OCCASION. INSTEAD IT THE LIGHTS REMAINED ON AND SO I IMMEDIATELY DROVE THE CAR BACK INTO THE REPAIR SHOP. THE REPAIR SHOP KEPT THE VEHICLE FOR SEVERAL DAYS TRYING TO ISOLATE THE CAUSE. EVENTUALLY THEY FOUND SOME SERIOUS CORROSION IN THE ESP/HYDRAULIC CONTROL UNIT. THEY TOLD ME THAT THIS WAS RELATED TO AN ACCIDENT THE CAR WAS INVOLVED IN AND SUGGESTED I CONTACT MY INSURER. THE INSURANCE ASSESSOR EXAMINED THE CAR IN DETAIL AND CONCLUDED THAT THE FAULT WAS ENTIRELY UNRELATED AND THEIR DIAGNOSIS WAS THAT THE DESIGN OF THE UNIT WAS FLAWED. IN OTHER WORDS THIS IS A DESIGN FAULT. THEY SAID THAT GIVEN THAT THIS UNIT CONTROLS THE ENTIRE BRAKING SYSTEM, ANY FAILURE COULD BE CATASTROPHIC. I HAD NO CHOICE BUT TO AUTHORIZE THE REPAIR. HOWEVER, I AM VERY CONCERNED ABOUT THIS ISSUE. THE UNIT HAS BEEN REPLACED AT A COST OF NEARLY $2,400 BUT IF AS THE GEICO INSURANCE ASSESSOR BELIEVES, THIS IS A DESIGN FAULT THEN THIS IS GOING TO HAPPEN AGAIN. ADDITIONALLY, IT SEEMS THAT THE UNIT HAD BEEN CORRODED FOR SOME TIME AND COULD HAVE FAILED AT ANY TIME BUT BECAUSE IT IS SUCH A COMMON OCCURRENCE FOR THESE WARNING LIGHTS TO COME ON, NO-ONE INVESTIGATED THE ISSUE WITH THE UNIT UNTIL RECENTLY. MY RELATED CONCERN IS THAT THE UNIT COULD FAIL AT ANY TIME AND THIS POSSIBILITY PLACES ME AND MY FAMILY IN POTENTIAL DANGER. MERCEDES DECLINED TO TAKE ANY ACTION. *TR
NHTSA ODI #10453913
83,367 miles · Jun 14, 2011
Vehicle Speed Control
TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT WAS DRIVING WITH THE CRUISE CONTROL ACTIVATED WHEN THE VEHICLE ABNORMALLY ACCELERATED UP TO 90 MPH. THE CONTACT WAS UNABLE TO DISENGAGE THE CRUISE CONTROL ALTHOUGH SHE WAS DEPRESSING THE BREAK PEDAL. THE VEHICLE WAS TAKEN TO THE DEALER WHO DIAGNOSED THAT THE ACCELERATO…
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TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT WAS DRIVING WITH THE CRUISE CONTROL ACTIVATED WHEN THE VEHICLE ABNORMALLY ACCELERATED UP TO 90 MPH. THE CONTACT WAS UNABLE TO DISENGAGE THE CRUISE CONTROL ALTHOUGH SHE WAS DEPRESSING THE BREAK PEDAL. THE VEHICLE WAS TAKEN TO THE DEALER WHO DIAGNOSED THAT THE ACCELERATOR, CRUISE CONTROL AND THE ELECTRIC KIT WERE DEFECTIVE AND NEEDED TO BE REPLACED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE VEHICLE WAS REPAIRED. THE FAILURE MILEAGE WAS 83,367 AND THE CURRENT MILEAGE WAS 113,000.
NHTSA ODI #10406806
104,000 miles · Jun 3, 2011
Unknown Or OtherFire
AFTER PARKING THE CAR A SMELL OF SMOKE WAS NOTED. THE CAR HAD BEEN DRIVING VERY WELL AND WAS RECENTLY SERVICED BY A MERCEDES DEALERSHIP WHICH INCLUDED A NEW BATTERY AMONG OTHER THINGS. BLACK SMOKE WAS NOTED COMING OUT OF THE HOOD. AS IT WAS ATTEMPTED TO POP OPEN THE HOOD, FLAMES DARTED INTO THE COMPARTMENT THROUGH A CREATED H…
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AFTER PARKING THE CAR A SMELL OF SMOKE WAS NOTED. THE CAR HAD BEEN DRIVING VERY WELL AND WAS RECENTLY SERVICED BY A MERCEDES DEALERSHIP WHICH INCLUDED A NEW BATTERY AMONG OTHER THINGS. BLACK SMOKE WAS NOTED COMING OUT OF THE HOOD. AS IT WAS ATTEMPTED TO POP OPEN THE HOOD, FLAMES DARTED INTO THE COMPARTMENT THROUGH A CREATED HOLE JUST UNDER THE GLOVE COMPARTMENT. FLAMES WERE NOTED COMING OUT OF THE HOOD, AROUND THE TIRES AND SOON ENGULFING THE ENTIRE FRONT OF THE CAR. THE FLAMES WERE PUT OUT BY THE FIRE DEPT. THE CAR IS A TOTAL LOSS. THE ENTIRE ENGINE AND IT'S COMPONENTS COMPLETELY DISINTEGRATED, THE INTERIOR FILLED WITH BLACK SOOT AND ODOR. THIS WAS A HUGE SHOCK AND SURPRISE TO THE OWNER SINCE THE VEHICLE WAS DRIVING SO WELL AND NEVER HAD A SERIOUS PROBLEM BEFORE.
NHTSA ODI #10405107
115,000 miles · May 23, 2011
Electrical SystemVehicle Speed Control
RUN OVER THE ANY PUMP ON THE ROAD THAT CAUSE THE GAS PEDAL PUSH DOWN TO THE BOTTOM, STILL DIDN'T ACCELERATE CAUSE THE CAR SLOWLY DOWN, THIS CAUSE EVERYTIME DRIVER OVER THE PUMP. *TR
NHTSA ODI #10402400
109,340 miles · Apr 23, 2011
Air BagsCrash
I WAS INVOLVED IN AN ACCIDENT A DRIVER RAN A STOP SIGN (HE MUST HAVE BEEN DOING 60+ MPH) HIT MY CAR ON THE FROM DRIVER SIDE. THE IMPACT WAS SO INTENSE THAT I HIT THE SIDE WINDOW WITH MY HEAD MY CAR THAT WAS GOING STRAIGHT DID A 90 DEGREE TURN AND THE AIR BAGS NEVER DEPLOYED. MY CAR IS A 2002 ML320. *TR
NHTSA ODI #10397223
112,000 miles · Jan 9, 2011
Electronic Stability Control (esc)Vehicle Speed Control
TO WHOM IT MAY CONCERN, I HAD A NEAR DEATH EXPERIENCE WHILE DRIVING ONE OF YOUR VEHICLES. I AM THE OWNER OF A MERCEDES 2002 ML320, WHICH WAS PURCHASED AT A PHILLIPS MERCEDES DEALERSHIP IN VIRGINIA BEACH VA. I NEED TO ADDRESS A VERY SERIOUS INCIDENT THAT OCCURRED OVER THE WEEKEND (DECEMBER 18, 2010). I WAS DRIVING BACK FROM RIC…
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TO WHOM IT MAY CONCERN, I HAD A NEAR DEATH EXPERIENCE WHILE DRIVING ONE OF YOUR VEHICLES. I AM THE OWNER OF A MERCEDES 2002 ML320, WHICH WAS PURCHASED AT A PHILLIPS MERCEDES DEALERSHIP IN VIRGINIA BEACH VA. I NEED TO ADDRESS A VERY SERIOUS INCIDENT THAT OCCURRED OVER THE WEEKEND (DECEMBER 18, 2010). I WAS DRIVING BACK FROM RICHMOND GOING TOWARD VIRGINIA BEACH, I WAS DRIVING 70 MPH ON I-64 AND HAD IT ON CRUISE CONTROL, AHEAD I SAW THAT TRAFFIC SLOWING DOWN SO I STEPPED ON THE BREAK; I THEN REALIZED THAT MY BRAKES WEREN'T WORKING AND I WAS UNABLE TO STOP OR SLOW THE CAR DOWN. I ATTEMPTED TO PUSH THE BREAK PEDAL DOWN AND IT WOULDN'T NUDGE EVEN THOUGH I APPLIED ALL OF MY WEIGHT TO IT, THE SPEED DID NOT DIMINISH AT ALL, I THEN TRIED THE EMERGENCY BRAKE AND THAT ALSO FAILED TO SLOW ME DOWN, MY FRIEND SUGGESTED THAT I PUT THE CAR IN NEUTRAL AND THEN TRY THE BRAKE, FORTUNATELY THAT WORKED AND WAS FINALLY ABLE TO COME TO A COMPLETE STOP. IT WAS ONE OF THE SCARIEST EXPERIENCES OF MY LIFE. YOUR PRODUCT PUT MY FRIEND'S AND MY LIFE IN JEOPARDY. I HAD THE BAS/ESP LIGHT COME ON IN THE PASS AND HAVE BROUGHT IT IN FOR REPAIRS 3 TIMES ALREADY: 07/27/2005, 12/01/2009 AND IN 10/19/2010. I AM STUNNED THAT A COMPANY WHO HAS SUCH A GREAT REPUTATION AND SEEMS TO THRIVE ON CUSTOMER SATISFACTION DROPPED THE BALL. AT NO POINT IN TIME DID ANY OF THE TECHNICIANS WHO PERFORMED THE REPAIRS ON MY CAR ADVISE ME OF THE POTENTIAL DANGER. *TR
NHTSA ODI #10375310
166,027 miles · Dec 30, 2010
SeatsFire
AFTER BEING ON FOR ABOUT FIVE MINUTES THE DRIVER'S SEAT HEATER OVERHEATED RESULTING IN A STRONG BURNING SMELL, BURN MARK ON THE CAR SEAT AND A RED BURN MARK ON MY BOTTOM. THE SEAT CONTINUED TO BE VERY HOT EVEN WHEN TURNED OFF. *TR
NHTSA ODI #10373435
128,000 miles · Oct 10, 2010
Electrical SystemFire
ML 320 GOT IN FIRE ITSELF SUDDENLY START AT THE LEFT FRONT SIDE OF THE ENGINE,I WAS DRIVING MY CAR FOR 5 MIN ON FWY, WHEN A CAR NEXT LINE HONK ON ME AND YELLED ME MY CAR HAS FIRE UNDER THE ENGINE AFTER THAT TRY TO STOP AND THE BRAKE PEDAL DID NOT WORK I HAVE TO STOP THE CAR WITH THE PARKING BRAKE AND RUN AWAY FROM THE VEHICLE.…
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ML 320 GOT IN FIRE ITSELF SUDDENLY START AT THE LEFT FRONT SIDE OF THE ENGINE,I WAS DRIVING MY CAR FOR 5 MIN ON FWY, WHEN A CAR NEXT LINE HONK ON ME AND YELLED ME MY CAR HAS FIRE UNDER THE ENGINE AFTER THAT TRY TO STOP AND THE BRAKE PEDAL DID NOT WORK I HAVE TO STOP THE CAR WITH THE PARKING BRAKE AND RUN AWAY FROM THE VEHICLE. *TR
NHTSA ODI #10359922
89,670 miles · Aug 2, 2010
Fuel System, Other
THE VEHICLE SUDDENLY LOSES ACCELERATION CAUSING IT TO SLOW DOWN ON FREEWAY WHEN MERGING,GOING UP HILLS OR IN FAST TRAFFIC. IF YOU PUSH GAS PEDAL TO FLOOR VEHICLE DOES NOT IMMEDIATELY RESPOND THEN SUDDENLY RE ACCELERATES. MECHANIC REPLACED ELECTRICAL PART CALLED THROTTLE PEDAL SENSOR WHICH IS IN ENGINE COMPARTMENT. THIS PART EL…
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THE VEHICLE SUDDENLY LOSES ACCELERATION CAUSING IT TO SLOW DOWN ON FREEWAY WHEN MERGING,GOING UP HILLS OR IN FAST TRAFFIC. IF YOU PUSH GAS PEDAL TO FLOOR VEHICLE DOES NOT IMMEDIATELY RESPOND THEN SUDDENLY RE ACCELERATES. MECHANIC REPLACED ELECTRICAL PART CALLED THROTTLE PEDAL SENSOR WHICH IS IN ENGINE COMPARTMENT. THIS PART ELECTRONICALLY SENDS SIGNAL TO ENGINE TO ACCELERATE OR NOT. WHEN IT FAILS THE ACCELERATION IS ERRATIC. CAN CAUSE UNINTENDED ACCELERATION OR LOSS OF IT. SAME PROBLEM HAPPENED WITH CO WORKER. *TR
NHTSA ODI #10346848
88,000 miles · Jun 21, 2010
Vehicle Speed Control
TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED WHILE DRIVING AT APPROXIMATE SPEEDS OF 60MPH, THE VEHICLE ABNORMALLY ACCELERATED TO SPEEDS OF 70 MPH WITHOUT DRIVER INTENT. THE CONTACT ATTEMPTED TO APPLY THE BRAKES BUT TO NO AVAIL. SHE THEN APPLIED ABRUPT PRESSURE TO THE BRAKE PEDAL USING BOTH FEET AND THE VE…
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TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED WHILE DRIVING AT APPROXIMATE SPEEDS OF 60MPH, THE VEHICLE ABNORMALLY ACCELERATED TO SPEEDS OF 70 MPH WITHOUT DRIVER INTENT. THE CONTACT ATTEMPTED TO APPLY THE BRAKES BUT TO NO AVAIL. SHE THEN APPLIED ABRUPT PRESSURE TO THE BRAKE PEDAL USING BOTH FEET AND THE VEHICLE BEGAN TO SLOWLY DECREASE IN SPEED. SHE WAS ABLE TO STOP THE VEHICLE BY ENGAGING THE EMERGENCY BRAKE AND SHIFTING INTO NEUTRAL. THE VEHICLE WAS TOWED TO THE DEALER WHERE SHE WAS AWAITING DIAGNOSTIC TESTING. THE FAILURE AND CURRENT MILEAGES WERE APPROXIMATELY 88,000.
NHTSA ODI #10339356
NHTSA investigations
1PE10050 · Brake Lamp Switch Failure.
Opened Dec 21, 2010 · Closed May 4, 2011
Status: closed (inferred from source dates) · Exterior Lighting:brake Lights:switch; Service Brakes, Hydraulic; Vehicle Speed Control; Vehicle Speed Control:cruise Control
ODI opened the investigation based on reports that the subject vehicle brake lamp switch (switch) failure caused 1) inoperative brake lamps (stay on or fail to illuminate), and/or 2) shift interlock failure (shifter locked in park), and/or 3) the cruise control to fail to cancel with brake application.Consumers also reported the illumination of a warning lamp on the instrument panel.The switch contains three sets of electrical contacts and a (normally extended) spring loaded plunger that actuates the contacts as it moves.As installed in the vehicle, the plunger contacts the brake pedal arm and is pushed into the switch; as the driver applies the pedal the plunger extends.One set of contacts (BLS) operates the stop lamps, a second set (EWM) controls the shift interlock system, and a third set (BS) is used by an on-board diagnostic (OBD) system to monitor switch operation.The cruise control monitors the BLS signal to determine when the brake is applied, the primary way the system is disabled when set.The relative timing of contact actuation in response to plunger movement allows the OBD system to detect a switch fault.When a fault is detected a malfunction indication lamp (MIL) is illuminated (driver alert), a diagnostic trouble code (DTC) is stored (for the service technician), and cruise control operation is inhibited (as a failsafe).In its response to ODI's January 2011 information request letter, MB explained its assessment of switch failures which was based primarily on evaluation of field return failures.MB identified both 1) electrical contact and 2) mechanical switch failure mechanisms.According to MB's analysis, electrical contact failure is the predominate failure type and the failure consequence depends on which contact fails.For instance MB claims that BLS contact failures are momentary in nature and do not affect brake light operation but are nonetheless detected by the OBD system, resulting in a DTC and subsequent replacement.Electrical contact failures of the BS and EWM contacts result in a DTC also, and EWM contact failures result in the shifter being stuck in the park (which can be overridden by the consumer).Accordingly MB maintains that electrical contact failures of the switch have no safety consequence since the brake lamps remain operational and the cruise control is always disabled.MB determined that mechanical failures of the switch, which are rare in their assessment, can result from internal wear and/or increased switch operating temperatures.High temperatures occur due to overheating of the BLS contacts and can cause the internal plastic components to melt.In one scenario overheated BLS contacts may melt to the extended plunger and are damaged when the brake pedal is released resulting in the brake lights staying on.In another scenario the increased temperatures and/or internal wear can cause the plunger to stick in the fully depressed position.In this case the cruise may not cancel when the brake is applied and the driver may have to use high brake pedal forces or other means (shifting to neutral or using the cruise master switch) to disengage the cruise.Additionally the vacuum assist can be depleted if the driver pumps the brakes resulting in reduced braking effectiveness and even higher pedal forces.In its March 31, 2011 defect notification, MB stated that to remediate the potential need for excessive brake force it would conduct a safety recall (11V-208) to replace the switch with a more robustly designed component.The recall includes 136,751 model year 2000 - 2002 M-Class and model year 2000 - 2004 M-Class AMG vehicles.Owner notification letters will be mailed
Additional source detail variants (4)
Exterior Lighting:brake Lights:switch
ODI opened the investigation based on reports that the subject vehicle brake lamp switch (switch) failure caused 1) inoperative brake lamps (stay on or fail to illuminate), and/or 2) shift interlock failure (shifter locked in park), and/or 3) the cruise control to fail to cancel with brake application.Consumers also reported the illumination of a warning lamp on the instrument panel.The switch contains three sets of electrical contacts and a (normally extended) spring loaded plunger that actuates the contacts as it moves.As installed in the vehicle, the plunger contacts the brake pedal arm and is pushed into the switch; as the driver applies the pedal the plunger extends.One set of contacts (BLS) operates the stop lamps, a second set (EWM) controls the shift interlock system, and a third set (BS) is used by an on-board diagnostic (OBD) system to monitor switch operation.The cruise control monitors the BLS signal to determine when the brake is applied, the primary way the system is disabled when set.The relative timing of contact actuation in response to plunger movement allows the OBD system to detect a switch fault.When a fault is detected a malfunction indication lamp (MIL) is illuminated (driver alert), a diagnostic trouble code (DTC) is stored (for the service technician), and cruise control operation is inhibited (as a failsafe).In its response to ODI's January 2011 information request letter, MB explained its assessment of switch failures which was based primarily on evaluation of field return failures.MB identified both 1) electrical contact and 2) mechanical switch failure mechanisms.According to MB's analysis, electrical contact failure is the predominate failure type and the failure consequence depends on which contact fails.For instance MB claims that BLS contact failures are momentary in nature and do not affect brake light operation but are nonetheless detected by the OBD system, resulting in a DTC and subsequent replacement.Electrical contact failures of the BS and EWM contacts result in a DTC also, and EWM contact failures result in the shifter being stuck in the park (which can be overridden by the consumer).Accordingly MB maintains that electrical contact failures of the switch have no safety consequence since the brake lamps remain operational and the cruise control is always disabled.MB determined that mechanical failures of the switch, which are rare in their assessment, can result from internal wear and/or increased switch operating temperatures.High temperatures occur due to overheating of the BLS contacts and can cause the internal plastic components to melt.In one scenario overheated BLS contacts may melt to the extended plunger and are damaged when the brake pedal is released resulting in the brake lights staying on.In another scenario the increased temperatures and/or internal wear can cause the plunger to stick in the fully depressed position.In this case the cruise may not cancel when the brake is applied and the driver may have to use high brake pedal forces or other means (shifting to neutral or using the cruise master switch) to disengage the cruise.Additionally the vacuum assist can be depleted if the driver pumps the brakes resulting in reduced braking effectiveness and even higher pedal forces.In its March 31, 2011 defect notification, MB stated that to remediate the potential need for excessive brake force it would conduct a safety recall (11V-208) to replace the switch with a more robustly designed component.The recall includes 136,751 model year 2000 - 2002 M-Class and model year 2000 - 2004 M-Class AMG vehicles.Owner notification letters will be mailed
Service Brakes, Hydraulic
ODI opened the investigation based on reports that the subject vehicle brake lamp switch (switch) failure caused 1) inoperative brake lamps (stay on or fail to illuminate), and/or 2) shift interlock failure (shifter locked in park), and/or 3) the cruise control to fail to cancel with brake application.Consumers also reported the illumination of a warning lamp on the instrument panel.The switch contains three sets of electrical contacts and a (normally extended) spring loaded plunger that actuates the contacts as it moves.As installed in the vehicle, the plunger contacts the brake pedal arm and is pushed into the switch; as the driver applies the pedal the plunger extends.One set of contacts (BLS) operates the stop lamps, a second set (EWM) controls the shift interlock system, and a third set (BS) is used by an on-board diagnostic (OBD) system to monitor switch operation.The cruise control monitors the BLS signal to determine when the brake is applied, the primary way the system is disabled when set.The relative timing of contact actuation in response to plunger movement allows the OBD system to detect a switch fault.When a fault is detected a malfunction indication lamp (MIL) is illuminated (driver alert), a diagnostic trouble code (DTC) is stored (for the service technician), and cruise control operation is inhibited (as a failsafe).In its response to ODI's January 2011 information request letter, MB explained its assessment of switch failures which was based primarily on evaluation of field return failures.MB identified both 1) electrical contact and 2) mechanical switch failure mechanisms.According to MB's analysis, electrical contact failure is the predominate failure type and the failure consequence depends on which contact fails.For instance MB claims that BLS contact failures are momentary in nature and do not affect brake light operation but are nonetheless detected by the OBD system, resulting in a DTC and subsequent replacement.Electrical contact failures of the BS and EWM contacts result in a DTC also, and EWM contact failures result in the shifter being stuck in the park (which can be overridden by the consumer).Accordingly MB maintains that electrical contact failures of the switch have no safety consequence since the brake lamps remain operational and the cruise control is always disabled.MB determined that mechanical failures of the switch, which are rare in their assessment, can result from internal wear and/or increased switch operating temperatures.High temperatures occur due to overheating of the BLS contacts and can cause the internal plastic components to melt.In one scenario overheated BLS contacts may melt to the extended plunger and are damaged when the brake pedal is released resulting in the brake lights staying on.In another scenario the increased temperatures and/or internal wear can cause the plunger to stick in the fully depressed position.In this case the cruise may not cancel when the brake is applied and the driver may have to use high brake pedal forces or other means (shifting to neutral or using the cruise master switch) to disengage the cruise.Additionally the vacuum assist can be depleted if the driver pumps the brakes resulting in reduced braking effectiveness and even higher pedal forces.In its March 31, 2011 defect notification, MB stated that to remediate the potential need for excessive brake force it would conduct a safety recall (11V-208) to replace the switch with a more robustly designed component.The recall includes 136,751 model year 2000 - 2002 M-Class and model year 2000 - 2004 M-Class AMG vehicles.Owner notification letters will be mailed
Vehicle Speed Control:cruise Control
ODI opened the investigation based on reports that the subject vehicle brake lamp switch (switch) failure caused 1) inoperative brake lamps (stay on or fail to illuminate), and/or 2) shift interlock failure (shifter locked in park), and/or 3) the cruise control to fail to cancel with brake application.Consumers also reported the illumination of a warning lamp on the instrument panel.The switch contains three sets of electrical contacts and a (normally extended) spring loaded plunger that actuates the contacts as it moves.As installed in the vehicle, the plunger contacts the brake pedal arm and is pushed into the switch; as the driver applies the pedal the plunger extends.One set of contacts (BLS) operates the stop lamps, a second set (EWM) controls the shift interlock system, and a third set (BS) is used by an on-board diagnostic (OBD) system to monitor switch operation.The cruise control monitors the BLS signal to determine when the brake is applied, the primary way the system is disabled when set.The relative timing of contact actuation in response to plunger movement allows the OBD system to detect a switch fault.When a fault is detected a malfunction indication lamp (MIL) is illuminated (driver alert), a diagnostic trouble code (DTC) is stored (for the service technician), and cruise control operation is inhibited (as a failsafe).In its response to ODI's January 2011 information request letter, MB explained its assessment of switch failures which was based primarily on evaluation of field return failures.MB identified both 1) electrical contact and 2) mechanical switch failure mechanisms.According to MB's analysis, electrical contact failure is the predominate failure type and the failure consequence depends on which contact fails.For instance MB claims that BLS contact failures are momentary in nature and do not affect brake light operation but are nonetheless detected by the OBD system, resulting in a DTC and subsequent replacement.Electrical contact failures of the BS and EWM contacts result in a DTC also, and EWM contact failures result in the shifter being stuck in the park (which can be overridden by the consumer).Accordingly MB maintains that electrical contact failures of the switch have no safety consequence since the brake lamps remain operational and the cruise control is always disabled.MB determined that mechanical failures of the switch, which are rare in their assessment, can result from internal wear and/or increased switch operating temperatures.High temperatures occur due to overheating of the BLS contacts and can cause the internal plastic components to melt.In one scenario overheated BLS contacts may melt to the extended plunger and are damaged when the brake pedal is released resulting in the brake lights staying on.In another scenario the increased temperatures and/or internal wear can cause the plunger to stick in the fully depressed position.In this case the cruise may not cancel when the brake is applied and the driver may have to use high brake pedal forces or other means (shifting to neutral or using the cruise master switch) to disengage the cruise.Additionally the vacuum assist can be depleted if the driver pumps the brakes resulting in reduced braking effectiveness and even higher pedal forces.In its March 31, 2011 defect notification, MB stated that to remediate the potential need for excessive brake force it would conduct a safety recall (11V-208) to replace the switch with a more robustly designed component.The recall includes 136,751 model year 2000 - 2002 M-Class and model year 2000 - 2004 M-Class AMG vehicles.Owner notification letters will be mailed
Vehicle Speed Control
ODI opened the investigation based on reports that the subject vehicle brake lamp switch (switch) failure caused 1) inoperative brake lamps (stay on or fail to illuminate), and/or 2) shift interlock failure (shifter locked in park), and/or 3) the cruise control to fail to cancel with brake application.Consumers also reported the illumination of a warning lamp on the instrument panel.The switch contains three sets of electrical contacts and a (normally extended) spring loaded plunger that actuates the contacts as it moves.As installed in the vehicle, the plunger contacts the brake pedal arm and is pushed into the switch; as the driver applies the pedal the plunger extends.One set of contacts (BLS) operates the stop lamps, a second set (EWM) controls the shift interlock system, and a third set (BS) is used by an on-board diagnostic (OBD) system to monitor switch operation.The cruise control monitors the BLS signal to determine when the brake is applied, the primary way the system is disabled when set.The relative timing of contact actuation in response to plunger movement allows the OBD system to detect a switch fault.When a fault is detected a malfunction indication lamp (MIL) is illuminated (driver alert), a diagnostic trouble code (DTC) is stored (for the service technician), and cruise control operation is inhibited (as a failsafe).In its response to ODI's January 2011 information request letter, MB explained its assessment of switch failures which was based primarily on evaluation of field return failures.MB identified both 1) electrical contact and 2) mechanical switch failure mechanisms.According to MB's analysis, electrical contact failure is the predominate failure type and the failure consequence depends on which contact fails.For instance MB claims that BLS contact failures are momentary in nature and do not affect brake light operation but are nonetheless detected by the OBD system, resulting in a DTC and subsequent replacement.Electrical contact failures of the BS and EWM contacts result in a DTC also, and EWM contact failures result in the shifter being stuck in the park (which can be overridden by the consumer).Accordingly MB maintains that electrical contact failures of the switch have no safety consequence since the brake lamps remain operational and the cruise control is always disabled.MB determined that mechanical failures of the switch, which are rare in their assessment, can result from internal wear and/or increased switch operating temperatures.High temperatures occur due to overheating of the BLS contacts and can cause the internal plastic components to melt.In one scenario overheated BLS contacts may melt to the extended plunger and are damaged when the brake pedal is released resulting in the brake lights staying on.In another scenario the increased temperatures and/or internal wear can cause the plunger to stick in the fully depressed position.In this case the cruise may not cancel when the brake is applied and the driver may have to use high brake pedal forces or other means (shifting to neutral or using the cruise master switch) to disengage the cruise.Additionally the vacuum assist can be depleted if the driver pumps the brakes resulting in reduced braking effectiveness and even higher pedal forces.In its March 31, 2011 defect notification, MB stated that to remediate the potential need for excessive brake force it would conduct a safety recall (11V-208) to replace the switch with a more robustly designed component.The recall includes 136,751 model year 2000 - 2002 M-Class and model year 2000 - 2004 M-Class AMG vehicles.Owner notification letters will be mailed
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