NHTSA owner reports · September 18, 2026 snapshot.
What owners actually said
88 reports210,000 miles · May 5, 2015
Service Brakes
TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT WHILE DRIVING AT VARIOUS SPEEDS, THE BRAKES WOULD ERRONEOUSLY ACTIVATE AND ABRUPTLY STOP THE VEHICLE. THE CONTACT INDICATED THAT WHEN THE FAILURE OCCURS THE BAS/ESP SENSOR LIGHT WOULD ILLUMINATE. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER W…
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TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT WHILE DRIVING AT VARIOUS SPEEDS, THE BRAKES WOULD ERRONEOUSLY ACTIVATE AND ABRUPTLY STOP THE VEHICLE. THE CONTACT INDICATED THAT WHEN THE FAILURE OCCURS THE BAS/ESP SENSOR LIGHT WOULD ILLUMINATE. THE VEHICLE WAS NOT DIAGNOSED OR REPAIRED. THE MANUFACTURER WAS NOT NOTIFIED OF THE FAILURE. THE FAILURE MILEAGE WAS 210,000.
NHTSA ODI #10714724
67,000 miles · Feb 10, 2015
Service Brakes
TL*THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT WHILE DRIVING AT AN UNKNOWN SPEED, ALL OF THE WARNING LIGHTS ILLUMINATED. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHERE THE TECHNICIAN DIAGNOSED THAT THE ABS SYSTEM FAILED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAI…
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TL*THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT WHILE DRIVING AT AN UNKNOWN SPEED, ALL OF THE WARNING LIGHTS ILLUMINATED. THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC WHERE THE TECHNICIAN DIAGNOSED THAT THE ABS SYSTEM FAILED. THE VEHICLE WAS NOT REPAIRED. THE MANUFACTURER WAS NOT MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS 67,000.
NHTSA ODI #10682608
143,340 miles · Nov 22, 2014
Steering
I BOUGHT THIS CAR YESTERDAY FROM AN INDIVIDUAL OFF CRAIGSLIST AND THE POWER STEERING HAS GONE OUT 5 TIMES. SO FAR ONLY AT VERY LOW SPEEDS, BUT I HAVE LOOKED ONLINE AND SEEN NUMBERS COMPLAINTS WITH POWER STEERING FAILURE AT FASTER SPEEDS TOO. VERY UNSETTLING. THERE WERE A COUPLE OF RECALLS REGARDING THE CLAMPS AND HOSES, BUT U…
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I BOUGHT THIS CAR YESTERDAY FROM AN INDIVIDUAL OFF CRAIGSLIST AND THE POWER STEERING HAS GONE OUT 5 TIMES. SO FAR ONLY AT VERY LOW SPEEDS, BUT I HAVE LOOKED ONLINE AND SEEN NUMBERS COMPLAINTS WITH POWER STEERING FAILURE AT FASTER SPEEDS TOO. VERY UNSETTLING. THERE WERE A COUPLE OF RECALLS REGARDING THE CLAMPS AND HOSES, BUT UPON RESEARCH I FOUND THAT Y CAR HAS NO OPEN CAMPAIGNS. I GUESS THAT MEANS THEY FIXED THE PROBLEM. THERE IS AN OBVIOUS PROBLEM STILL AND I NEED IT FIXED OR I NEED A NEW CAR. THIS IS NOT SAFE. *TR
NHTSA ODI #10660267
149,000 miles · May 13, 2014
Electronic Stability Control (esc)Service BrakesSteering
WHILE DRIVING ON THE HIGHWAY AT 60MPH THE VEHICLE STARTED SHAKING VIOLENTLY. THE BRAKES STARTED ENGAGING ON THEIR OWN PULLING THE CAR TO THE LEFT AND RIGHT AND NEARLY BRINGING THE CAR TO A SUDDEN STOP. IT TOOK A LOT OF EFFORT TO KEEP THE VEHICLE FROM PULLING INTO THE OTHER LANES AND CAUSING AN ACCIDENT. THE BAS/ESP LIGHT CAME ON…
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WHILE DRIVING ON THE HIGHWAY AT 60MPH THE VEHICLE STARTED SHAKING VIOLENTLY. THE BRAKES STARTED ENGAGING ON THEIR OWN PULLING THE CAR TO THE LEFT AND RIGHT AND NEARLY BRINGING THE CAR TO A SUDDEN STOP. IT TOOK A LOT OF EFFORT TO KEEP THE VEHICLE FROM PULLING INTO THE OTHER LANES AND CAUSING AN ACCIDENT. THE BAS/ESP LIGHT CAME ON THE DASH AND HAS STAYED ON NOW. THIS ALL LASTED FOR ABOUT 10 SECONDS. I WAS IN THE 3RD LANE OF A 4 LANE HIGHWAY DURING MODERATE TRAFFIC. I WAS ALMOST REAR ENDED BY TWO DIFFERENT VEHICLES. I HAVE BEEN RESEARCHING THIS ISSUE AND FOUND MANY OTHER DRIVERS WITH THE SAME THING. THIS IS A DANGEROUS DEFECT AND NEEDS TO BE ADDRESSED. IT DOESN'T TAKE MUCH FOR A SUDDEN CHANGE IN DIRECTION AND SPEED TO CAUSE A SEVERE ACCIDENT WHEN DRIVING ON THE HIGHWAY, AND KNOWING THAT THIS VEHICLE IS CAPABLE AND KNOW FOR DOING THIS MAKES IT VERY DANGEROUS. IT MAKES ME WONDER HOW MANY FATAL ACCIDENTS HAVE OCCURRED DUE TO THIS PROBLEM, BUT NO ONE KNEW BECAUSE IT WAS JUST ASSUMED THE TO BE DRIVER ERROR. *TR
NHTSA ODI #10587996
98,224 miles · Apr 22, 2013
Engine And Engine CoolingSteering
DRIVING HOME ON A LOCAL STREET AT ABOUT 30 MILES PER HOUR, APPROACHING INTERSECTION, TRYING TO TURN, ALL THE SUDDEN, STEERING WHEEL BECAME VERY HARD TO TURN, WITH NO ASSISTING POWER, CAR RUN OVER TO THE OTHER SIDE OF THE ROAD, ALMOST CRASH INTO CURB. IT IS VERY LUCKY, THERE IS NO INCOMING CARS, WOULD HAVE CRASH HEAD ON OTHERW…
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DRIVING HOME ON A LOCAL STREET AT ABOUT 30 MILES PER HOUR, APPROACHING INTERSECTION, TRYING TO TURN, ALL THE SUDDEN, STEERING WHEEL BECAME VERY HARD TO TURN, WITH NO ASSISTING POWER, CAR RUN OVER TO THE OTHER SIDE OF THE ROAD, ALMOST CRASH INTO CURB. IT IS VERY LUCKY, THERE IS NO INCOMING CARS, WOULD HAVE CRASH HEAD ON OTHERWISE. CAR TOWED TO DEALER, FOUND STEERING HOSE FROM RADIATOR TO STEERING RACK BROKEN OFF, STEERING FLUID SPLATTING ALL OVER ENGINE. DEALER STATED NO RECALL FOR STEERING HOSE COMING OUT OF RADIATOR, BUT THERE WAS RECALL ON STEERING HOSE COMING OUT OF PUMP. SO THIS DEFECT WAS NOT COVERED. I URGE NHTSA TO INVESTIGATE THIS DANGEROUS DEFECT IMMEDIATELY, AND ISSUE RECALL TO SAVE LIVES. *TR
NHTSA ODI #10509207
90,000 miles · Apr 10, 2013
VisibilityInjury
TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT WHILE DRIVING 70 MPH, A LOUD NOISE HEARD AS THE SUN ROOF EXPLODED INTO THOUSANDS OF GLASS SHARDS. THE DRIVER AND PASSENGER BOTH SUSTAINED LACERATIONS FROM THE BROKEN GLASS. A DEALER WAS NOTIFIED AND ADVISED THE CONTACT TO GO TO A SALVAGE YARD FOR PARTS TO …
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TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT WHILE DRIVING 70 MPH, A LOUD NOISE HEARD AS THE SUN ROOF EXPLODED INTO THOUSANDS OF GLASS SHARDS. THE DRIVER AND PASSENGER BOTH SUSTAINED LACERATIONS FROM THE BROKEN GLASS. A DEALER WAS NOTIFIED AND ADVISED THE CONTACT TO GO TO A SALVAGE YARD FOR PARTS TO REPAIR THE VEHICLE HIMSELF. THE MANUFACTURER WAS NOTIFIED BUT OFFERED NO ASSISTANCE. THE VEHICLE WAS NOT REPAIRED. THE FAILURE AND CURRENT MILEAGE WAS 90,000. ...UPDATED 06-19-13 *BF UPDATED 06/26/2013*JS
NHTSA ODI #10505853
120,000 miles · Mar 17, 2013
Electrical SystemUnknown Or OtherVehicle Speed Control
MY 2002 ML320 CLUSTER DISPLAY LIGHTS ON MY DASH ALL LIGHT UP, THE CHECK ENGINE LIGHT COMES ON, THE SPEEDOMETER STOPS WORKING ACTUALLY GOES TO ZERO. ONCE THE CAR COMES TO A COMPLETE STOP IT ACCELERATES VERY SLOWLY AND WILL NOT SHIFT OUT OF FIRST GEAR. THIS IS VERY FRIGHTENING FOR SOMEONE IN TRAFFIC AND THIS HAPPENS WITHOUT WARN…
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MY 2002 ML320 CLUSTER DISPLAY LIGHTS ON MY DASH ALL LIGHT UP, THE CHECK ENGINE LIGHT COMES ON, THE SPEEDOMETER STOPS WORKING ACTUALLY GOES TO ZERO. ONCE THE CAR COMES TO A COMPLETE STOP IT ACCELERATES VERY SLOWLY AND WILL NOT SHIFT OUT OF FIRST GEAR. THIS IS VERY FRIGHTENING FOR SOMEONE IN TRAFFIC AND THIS HAPPENS WITHOUT WARNING. PLEASE INVESTIGATE THIS ISSUE BEFORE SOMEONE IS REAR ENDED AND DIES. *TR
NHTSA ODI #10503370
69,000 miles · Mar 10, 2013
Service Brakes
THE ANTI-LOCK BRAKING SYSTEM WOULD ENGAGE WITHOUT DRIVER ACTIVATION. THE BAS/ESP LIGHT WOULD COME ON WITHOUT ANY REASON EITHER. ONE DAY I WAS ON THE FREEWAY WHEN IT HAPPENED AND SUDDENLY THE BREAKS WERE ENGAGED AT 73 MPH WHEN I WAS ON THE FAST LANE AND OTHER VEHICLES FOLLOWING AT ABOUT THE SAME SPEED. MY LEG WAS ON THE ACCELERAT…
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THE ANTI-LOCK BRAKING SYSTEM WOULD ENGAGE WITHOUT DRIVER ACTIVATION. THE BAS/ESP LIGHT WOULD COME ON WITHOUT ANY REASON EITHER. ONE DAY I WAS ON THE FREEWAY WHEN IT HAPPENED AND SUDDENLY THE BREAKS WERE ENGAGED AT 73 MPH WHEN I WAS ON THE FAST LANE AND OTHER VEHICLES FOLLOWING AT ABOUT THE SAME SPEED. MY LEG WAS ON THE ACCELERATOR GASSING TO CONTINUE, BUT THE ANTI-LOCK BRAKING SYSTEM FORCED THE CAR TO ALMOST A STOP - ABOUT 10MPH, BEFORE THE BREAKS DISENGAGED AND THE CAR CONTINUED TO MOVE (THAT IS ACCELERATE AGAIN). I ALMOST GOT RAMMED BY THE VEHICLE BEHIND ME. I TOOK IT TO MECERDES BENZ DEALERSHIP IN GEORGE TOWN TX. THEY SAID IT WAS UNEQUAL SIZE TIRES THAT WAS THE PROBLEM. I CHANGED THE TIRES TO ALL NEW AND THE SAME SIZE TRIES AND THE PROBLEM PERSISTED. I TOOK IT BACK TO THE GEORGETOWN DEALERSHIP AGAIN. THIS TIME THEIR DIAGNOSIS WAS THAT THE LATERAL ACCELERATION AND YAW SENSORS WERE FAULTY AND NEEDED TO BE REPLACED FOR $1250.00. WHAT I DESCRIBED ABOVE WAS JUST AN EPISODE. IT HAPPEN FIRST WHEN MY WIFE WAS DRIVING THE CAR. IT HAS HAPPENED SEVERAL OTHER TIMES BEFORE I FINALLY TOOK IT FOR REPAIRS. I HAVE PACKED THE CAR FOR NOW BECAUSE I HAVE OTHER CARS TO USE AND THE PROBLEM HAS NOT STILL BEEN FIXED. NHTSA SHOULD ISSUE A RECALL. *TR
NHTSA ODI #10502267
79,000 miles · Feb 10, 2013
Steering
POWER STEERING O RING AND HOSE RECALL. *TR
NHTSA ODI #10497609
129,000 miles · Nov 8, 2012
Electronic Stability Control (esc)Service BrakesSteering
FRONT PASSENGER SIDE WHEEL BRAKE ON IT'S OWN, PULLING ME OFF TO THE LEFT OF THE ROAD VEHICLE BRAKE (RIGHT SIDE) STAYED ENGAGED UNTIL VEHICLE SPEED WAS DOWN TO ABOUT 20 MPH. DEALER SAID A BAD YAW RATE SENSOR WAS THE PROBLEM. *TR
NHTSA ODI #10483756
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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