NHTSA owner reports · September 18, 2026 snapshot.
What owners actually said
88 reports22,000 miles · Jun 17, 2010
Service Brakes, Hydraulic
2002 ML 320 FRONT BRAKES LOCKED UP BY THEMSELVES NEARLY CAUSING AN ACCIDENT. BURNING SMELL DETECTED FROM FRONT WHEELS. VEHICLE TAKEN TO DEALER WHO CLAIMED SENSORS HAD FAILED AND THAT THIS WAS A RARE PROBLEM; CONSUMER CHARGED TO REPLACE SENSORS. LESS THAN ONE MONTH LATER THE SAME THING OCCURRED, DEALER NOW STATES IT IS A PRESSUR…
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2002 ML 320 FRONT BRAKES LOCKED UP BY THEMSELVES NEARLY CAUSING AN ACCIDENT. BURNING SMELL DETECTED FROM FRONT WHEELS. VEHICLE TAKEN TO DEALER WHO CLAIMED SENSORS HAD FAILED AND THAT THIS WAS A RARE PROBLEM; CONSUMER CHARGED TO REPLACE SENSORS. LESS THAN ONE MONTH LATER THE SAME THING OCCURRED, DEALER NOW STATES IT IS A PRESSURE ISSUE BUT WANTS TO KEEP VEHICLE OVERNIGHT TO DUPLICATE STATED PROBLEM. OWNER INITIALLY NOTICED THIS PROBLEM OVER 1 YEAR AGO, TAKING IT TO THE DEALER THINKING THE EMERGENCY BRAKE WAS STICKING, CAUSING THE BURNING SMELL AND SLUGGISHNESS. DURING THAT VISIT THE DEALER STATED IT FOUND NO PROBLEM WITH THE EMERGENCY BRAKE. OWNER PAID TO HAVE ROTORS AND BRAKE PADS REPLACED DUE TO PITTING AND GROVING CAUSED BY THE FRONT BRAKES SELF-ENGAGING; THIS DID NOT FIX THE PROBLEM AND THE DEALER IS CURRENTLY INVESTIGATING A PRESSURE ISSUE. VEHICLE HAS LESS THAN 24K MILES ON IT AND WAS PURCHASED FROM THE DEALER BRAND NEW. *TR
NHTSA ODI #10336836
118,206 miles · May 16, 2010
Service Brakes, HydraulicVehicle Speed Control
[MERCEDES BENZ ML 320 2002] WHILE DRIVING EAST ON ROUTE 80 AT 65 MPH AND APPROACHING THE TOLL BOOTHS OF THE GEORGE WASHINGTON BRIDGE, I TAPPED MY BRAKES TO DISENGAGE MY SPEED CONTROL. THE SPEED CONTROL DID NOT SHUT DOWN. I HIT THE BRAKE PEDAL SEVERAL MORE TIMES HARDER AND HARDER, BUT THE SPEED CONTROL STAYED IN CONTROL. I PUS…
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[MERCEDES BENZ ML 320 2002] WHILE DRIVING EAST ON ROUTE 80 AT 65 MPH AND APPROACHING THE TOLL BOOTHS OF THE GEORGE WASHINGTON BRIDGE, I TAPPED MY BRAKES TO DISENGAGE MY SPEED CONTROL. THE SPEED CONTROL DID NOT SHUT DOWN. I HIT THE BRAKE PEDAL SEVERAL MORE TIMES HARDER AND HARDER, BUT THE SPEED CONTROL STAYED IN CONTROL. I PUSHED DOWN VERY HARD ON THE BRAKE PEDAL WITH BOTH FEET AND ALTHOUGH THE CAR SLOWED A LITTLE, THE SPEED CONTROL DRAMATICALLY SPEEDED UP THE ENGINE WITH THE TACHOMETER GOING ALMOST FULL SCALE. I WAS ABLE TO REDUCE THE CAR'S SPEED FROM ABOUT 65 TO UNDER 50 MPH, BUT WAS STILL PRETTY SCARED. THIS WAS A TERRIFYING EXPERIENCE AND AS AN ENGINEER I REALIZED MY OPTIONS AND TIME TO REACT WERE VERY LIMITED! I FIGURED MY CHOICES WERE FEW: 1) BRAKE UNTIL THE CAR EITHER STOPPED OR I HAD HIT THE STOPPED CARS AT THE TOLL BOOTHS (MAYBE DAMAGE THE TRANSMISSION FURTHER), 2) SHIFT THE CAR INTO NEUTRAL HOPING THAT EITHER THE SPEED CONTROL WOULD DISENGAGE OR AT LEAST I COULD STOP THE CAR (ENGINE RPMS MIGHT RUN AWAY AND DESTROY THE ENGINE), OR 3) TRY TO SHUT OFF THE SPEED CONTROL WITH THE CONTROL STALK ON THE LEFT OF THE STEERING COLUMN (WHICH I OBVIOUSLY COULD NOT READ CLOSELY TO FIGURE OUT WHERE THE STOP MIGHT BE). FORTUNATELY, WITH SEVERAL TRIES I WAS ABLE TO FIND THE STOP POSITION ON THE SPEED CONTROL STALK AND DISENGAGE THE CONTROL. I BRAKED VERY HARD TO STOP SHORT OF A COLLISION..... AND GOT HARSH WORDS AND LOOKS FROM THE ADJACENT TOLL COLLECTORS. I SUSPECTED THAT THE BRAKE LIGHT SWITCH WAS NOT WORKING AND THIS WAS CONFIRMED BY MY MECHANIC (EDDIE RODRIGUEZ OF EDDY'S TOTAL AUTO CARE). THE MECHANIC ALSO HAS TO REPLACE THE BRAKE PRESSURE SENSOR. MY WIFE IS INSISTING THAT I GET RID OF THE CAR IMMEDIATELY AND BUY A NEW CAR. I LOVE MY ML 320..... BUT I LOVE MY WIFE TOO! *TR
NHTSA ODI #10330616
Mileage unknown · Apr 1, 2010
Electrical SystemEngine And Engine CoolingLatches/locks/linkages
2002 MERCEDES-BENZ ML320. CONSUMER IS HAVING SOME WARRANTY REPAIR PROBLEMS WITH MERCEDES-BENZ. HE ALSO STATES THAT MERCEDES-BENZ IS REFUSING TO PAY FOR ANY RECALL REPAIRS. *KB THE CONSUMER STATED NOISES AND LACK OF POWER FROM THE VEHICLE WERE REPORTED TO THE DEALER. AN INDEPENDENT REPAIR SHOP FOUND DIRTY SOLID METAL RESIDUE IN…
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2002 MERCEDES-BENZ ML320. CONSUMER IS HAVING SOME WARRANTY REPAIR PROBLEMS WITH MERCEDES-BENZ. HE ALSO STATES THAT MERCEDES-BENZ IS REFUSING TO PAY FOR ANY RECALL REPAIRS. *KB THE CONSUMER STATED NOISES AND LACK OF POWER FROM THE VEHICLE WERE REPORTED TO THE DEALER. AN INDEPENDENT REPAIR SHOP FOUND DIRTY SOLID METAL RESIDUE IN THE TRANSMISSION FLUID, THERE WERE MISSING PARTS IN THE PLANETARY GEAR. THE CAUSE OF DAMAGE WAS FAULTY ASSEMBLY OF THE PINS/PLUGS IN THE GEARS, WHICH RESULTED IN THE PARTS BECOMING LOOSE AND BREAKING THE TEETH, WHICH CAUSED EXCESSIVE NOISE AND LOSS OF POWER, ULTIMATELY THE TRANSMISSION WAS REPLACED. THE POWER STEERING WAS LEAKING, THE BRAKE AND ENGINE LIGHTS ILLUMINATED SEVERAL TIMES, THE CATALYTIC CONVERTER WAS REPLACED, THE DOOR LOCKS HAD TO BE REPAIRED, THE BATTERY WAS REPLACED AND THE SWAY BAR LINK BUSHING WERE REPLACED AS WELL. *JB UPDATED 06/01/10.*JB UPDATED 06/04/10.*JB UPDATED 10/18/10*JB UPDATED 10/29/10*JB
NHTSA ODI #10323089
85,000 miles · Feb 17, 2010
Steering
TL*THE CONTACT OWNS A 2002 MERCEDES ML320. WHILE DRIVING AT SPEEDS OF LESS THAN 50 MPH, THE STEERING LOCKED WITHOUT WARNING CAUSING THE WHEEL TO BECOME TREMENDOUSLY HARD TO TURN. SHE ALMOST LOST CONTROL OF THE VEHICLE, HOWEVER SHE WAS ABLE TO EVENTUALLY MANEUVER THE VEHICLE OFF OF HE HIGHWAY SAFELY. THE DEALER WAS CONTACTED AND …
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TL*THE CONTACT OWNS A 2002 MERCEDES ML320. WHILE DRIVING AT SPEEDS OF LESS THAN 50 MPH, THE STEERING LOCKED WITHOUT WARNING CAUSING THE WHEEL TO BECOME TREMENDOUSLY HARD TO TURN. SHE ALMOST LOST CONTROL OF THE VEHICLE, HOWEVER SHE WAS ABLE TO EVENTUALLY MANEUVER THE VEHICLE OFF OF HE HIGHWAY SAFELY. THE DEALER WAS CONTACTED AND SHE WAS ADVISED THAT THERE WAS AN OPEN RECALL CAMPAIGN ON THE VEHICLE (NHTSA CAMPAIGN ID NUMBER: 03V121000; STEERING, HYDRAULIC POWER ASSIST HOSE, PIPING, AND CONNECTIONS) AND ADVISED COMING IN FOR REPAIRS. NO REPAIRS WERE MADE TO DATE. THE FAILURE AND CURRENT MILEAGES WERE APPROXIMATELY 85,000.
NHTSA ODI #10311381
76,000 miles · Dec 29, 2009
Engine And Engine CoolingFire
TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. WHILE DRIVING UP A HILL THE VEHICLE BEGAN TO ACCELERATE VERY SLOWLY. HE PULLED OVER TO THE SIDE OF THE ROAD, OPENED THE HOOD, AND NOTICED SMOKE. WITHIN A FEW SECONDS, THE VEHICLE CAUGHT ON FIRE. HE WILL CONTACT THE MANUFACTURER. THE INSURANCE COMPANY WAS NOTIFIED. THE CURRENT…
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TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. WHILE DRIVING UP A HILL THE VEHICLE BEGAN TO ACCELERATE VERY SLOWLY. HE PULLED OVER TO THE SIDE OF THE ROAD, OPENED THE HOOD, AND NOTICED SMOKE. WITHIN A FEW SECONDS, THE VEHICLE CAUGHT ON FIRE. HE WILL CONTACT THE MANUFACTURER. THE INSURANCE COMPANY WAS NOTIFIED. THE CURRENT AND FAILURE MILEAGES WERE 76,000. THE VIN WAS NOT AVAILABLE.
NHTSA ODI #10297417
101,000 miles · Nov 23, 2009
SeatsFire
DRIVING 2002 MERCEDES ML320. SMELLED BURNING. PULLED OVER AND CHECKED UNDER HOOD AND FOUND NO SMELL. WHEN I GOT BACK INTO THE CAR, I NOTICED A BURNED SPOT ON THE DRIVERS SEAT. CORRESPONDING BURN MARK WAS ON MY BACK LEFT PANT POCKET. I TURNED OF THE SEAT WARMER AND THE PROBLEM HAS STOPPED. *TR
NHTSA ODI #10293230
Mileage unknown · Oct 1, 2009
Exterior LightingService Brakes, Hydraulic
I PURCHASED A USED 2002 ML320. ONCE THE VEHICLE CAME OF THE LOT IT WAS FINE IN THE BEGINNING; HOWEVER, THE BAS/ESP CONTINUES TO COME ON EVERY TWO TO THREE MONTHS. THIS PREVENTS ME FROM MOVING THE GEAR SHIFT FROM PARK TO DRIVE ALSO THE BRAKE LIGHTS ARE NOT WORKING (ON OR OFF WHEN PRESSING ON THE BRAKE PAD)AND WHEN IT DOES COME O…
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I PURCHASED A USED 2002 ML320. ONCE THE VEHICLE CAME OF THE LOT IT WAS FINE IN THE BEGINNING; HOWEVER, THE BAS/ESP CONTINUES TO COME ON EVERY TWO TO THREE MONTHS. THIS PREVENTS ME FROM MOVING THE GEAR SHIFT FROM PARK TO DRIVE ALSO THE BRAKE LIGHTS ARE NOT WORKING (ON OR OFF WHEN PRESSING ON THE BRAKE PAD)AND WHEN IT DOES COME ON WHEN I AM DRIVING AT NIGHT OTHER DRIVERS CANNOT SEE ANY BRAKE LIGHTS AT ALL WHICH PUTS MY FAMILY AND I IN A SAFETY SITUATION OR SAFETY HAZARD WHICH HAS OCCURRED MANY TIMES WHILE DRIVING. AT FIRST, I TOOK IT TO NAPA ON METRO PARKWAY IN FORT MYERS WHICH THEY REPLACED THE BRAKE LIGHT SWITCH AND THEN TWO MONTHS TO THREE MONTHS LATER THE VEHICLE WAS TAKEN BACK FOR THE SAME SITUATION. THEY REPLACED THE SWITCH AND SAID THE BRAKE LIGHT SWITCH THEY RECEIVED WAS FROM MERCEDES BENZ. IN THE SPRING 2007 THE SAME SITUATION OCCURRED AND TOOK IT TO MERCEDES BENZ OF FORT MYERS AND THEY ALSO REPLACED THE SWITCH AS WELL. HOWEVER, MERCEDES OF FORT MYERS CHANGED AND FOLLOWED ORDERS FROM CORPORATE ON WHAT TO DO BUT TO NO AVAIL. THIS HAS BEEN AN ONGOING ISSUE SINCE THE PURCHASED OF THE ML320. CURRENTLY, OCTOBER 1, 2009 THE VEHICLE IS AT MERCEDES AT FORT MYERS FOR THE SAME ISSUE. MY WIFE AND I HAVE CONTACTED MERCEDES CUSTOMER COMPLAINT WITH THIS ISSUE BUT WE FEEL ENOUGH IS NOT BEING DONE TO RESOLVE. THE SITUATION BEGAN IN THE MONTH OF DECEMBER 9, 2006 AND CONTINUES PRESENTLY WHICH I HAVE INDICATED. OTHER DRIVERS CAME CLOSE TO CRASHING INTO ME DUE TO NO BRAKES LIGHTS. MY WIFE AND I FEEL THAT WE PURCHASED A USED VEHICLE THAT IS CONSIDERED TO BE A LEMON THAT HAD ABOUT SEVENTY TWO PLUS THOUSAND MILES ON IT. THIS IS A VERY DANGEROUS SITUATION, AND MY WIFE AND I WOULD APPRECIATE IT IF YOU CAN INVESTIGATE THIS SITUATION. PLEASE RESPOND AS SOON AS POSSIBLE. *TR UPDATED IVOQ 10/11/11. *JB UPDATED IVOQ 10/18/11. *JB
NHTSA ODI #10286007
76,000 miles · Sep 25, 2009
Tires
2 OF MY TIRES DEVELOPED CRACKS IN THE SIDEWALL IN LESS THAN 24 MONTHS WITH PLENTY OF TREADLIFE LEFT ON THE THEM. *TR
NHTSA ODI #10285284
Mileage unknown · Aug 26, 2009
Steering
2002 MERCEDES BENZ ML320. SAFETY RECALL FOR POWER STEERING PUMP. CONSUMER STATES THAT SHE HAD THE REPAIR DONE PRIOR TO THE RECALL NOTICE. *NJ THE CONSUMER ENCOUNTERED PROBLEMS WITH THE POWER STEERING PUMP BACK IN 2007, BUT DIDN'T RECEIVE THE RECALL UNTIL 2009. *JB
NHTSA ODI #10282150
74,500 miles · Apr 27, 2009
Electrical SystemFire
I WAS DRIVING AT 40-45 MPH WHEN I NOTICED AN ORANGE GLOW UNDER THE PASSENGER SIDE MIRROR. WITHIN A FEW SECONDS THE LIGHT TURNED YELLOW, AND SUDDENLY I NOTICED FLAMES ARE SHOOTING OUT OF THE SIDE MIRROR ALONG WITH THICK BLACK SMOKE. I IMMEDIATELY TURNED INTO A GAS STATION AND PUT OFF THE FIRE WITH WATER HOSE. I WAS AFRAID OF THE …
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I WAS DRIVING AT 40-45 MPH WHEN I NOTICED AN ORANGE GLOW UNDER THE PASSENGER SIDE MIRROR. WITHIN A FEW SECONDS THE LIGHT TURNED YELLOW, AND SUDDENLY I NOTICED FLAMES ARE SHOOTING OUT OF THE SIDE MIRROR ALONG WITH THICK BLACK SMOKE. I IMMEDIATELY TURNED INTO A GAS STATION AND PUT OFF THE FIRE WITH WATER HOSE. I WAS AFRAID OF THE FIRE TO GET INSIDE THE CAR. *TR
NHTSA ODI #10267033
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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