IllustrationFUSE BOX SOME HAS POWER SOME NOT. FRONT LEFT WHEEL MAKING THIS NOISE AND STOPS AFTER 25 MILES PER HOUR RADIO VOLUME LOW WHEN IGNITION KEY IS ON POSITION 3 WHEN KEY IT'S IN THE POSITION 2 LAUD VOLUME WHEN KEY IS NOT IN I CAN TURN ON THE STEREO
2002 Mercedes Benz ML320
Owner reports · Recalls · Investigations
Similar to other model years
Owner complaints for the 2002 Mercedes Benz ML320 do not stand out strongly from the model-year median of 28.
About this comparison →How this year compares
Owner complaints by model year
Compare all ML320 years →Counts vary with age, sales and reporting. They are not failure rates.
What owners reported most
All reported categories
Tap a category to read its complaints. One report may name several components.
When problems were reported
Mileage at the reported incident
100–25K
525–50K
1150–75K
1175–100K
20100–150K
9150K+
66 reports with mileage · 22 unknown
NHTSA’s mileage field refers to the reported incident, not necessarily the filing date. This shows report counts, not the likelihood of a failure.
What to inspect
Issues worth paying extra attention to based on owner reports.
- Steering. Review the 24 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Electrical System. Review the 19 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
- Service Brakes. Review the 15 owner reports in this category and discuss these concerns during a pre-purchase inspection. Read reports →
NHTSA owner reports · September 18, 2026 snapshot.
4 crash reports8 fire reports5 injury reports
Electrical System complaints
19 reports"TAKATS RECALL" 1ST ISSUE I NOTICED IS WHEN I GAVE SOMEONE A JUMP OFF A DEAD CAR BATTERY. AS I WAS DRIVEN I NOTICED MY CAR BATTERY LIGHT CAME ON MEANING MY BATTERY WAS DECREASING POWER AND IT DID I WAS ON MY WAY HOME DRIVEN I NOTICED MY CAR LOSING POWER IN THE CAR SHUT COMPLETELY OFF SO I PULLED TO THE SIDE AND I CALLED SOMEONE …
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"TAKATS RECALL" 1ST ISSUE I NOTICED IS WHEN I GAVE SOMEONE A JUMP OFF A DEAD CAR BATTERY. AS I WAS DRIVEN I NOTICED MY CAR BATTERY LIGHT CAME ON MEANING MY BATTERY WAS DECREASING POWER AND IT DID I WAS ON MY WAY HOME DRIVEN I NOTICED MY CAR LOSING POWER IN THE CAR SHUT COMPLETELY OFF SO I PULLED TO THE SIDE AND I CALLED SOMEONE TO GIVE ME A JUMP THE CAR STARTED BACK UP DROVE ABOUT 3, BLOCKS AND THE CAR SHUT COMPLETELY OFF AGAIN SO I PURCHASED A BRAND NEW BATTERY REPLACING THE OLD BATTERY WITH AN NEW ONE. GOT ANOTHER JUMP TO GIVE THE THE BATTERY SOME EXTRA JUICE. AFTER I RECEIVED THE JUMP I'M BACK ON THE ROAD. IN THE ANCIENT OCCUR AGAIN SO I CALLED SOMEONE TO GIVE ME A JUMP. THIS TIME THE CAR DIDN'T START. SO I HAD TO GET IT TOW HOME. GOT HOME DID SOME RESEARCH IN FOUND OUT IT WAS THE ALTERNATOR. REPLACE THE OLD ALTERNATOR WITH A NEW ONE. 2ND ISSUE I NOTICED AFTER I REPLACED THE OLD ALTERNATOR WITH THE NEW ONE I NOTICED MY TWO FANS BLOWER WILL CONTINUOUSLY RUN FOR HOURS WHEN I TAKE MY CAR KEYS OUT OF THE IGNITION. AND DUE TO THAT THAT CAUSE MY DRAINED MY BATTERY CAUSING ME TO LOSE POWER AND MY CAR WON'T BE ABLE TO START WHEN I PUT MY KEY IN THE IGNITION I DON'T KNO IF THEY CONNECTED A WIRE TO KEEP RUNNING IF SO HE WAS TO SUPPOSED TO TELL ME THAT WHICH HE DIDN'T. 3RD ISSUE I NOTICED I RECENTLY ADDED NEW FRONT PADS AND ROTOR'S NEW REAR PADS AND ROTORS 1 NEW REAR PASSSGER SIDE BRAKE CALIPER. MY BRAKE LIGHTS STILL APPEARED TO POP UP I TOLD THE MERCHANT HE TOLD ME IT COULD BE A SENSOR FAILURE AND GET CHECK OUT AT A MERCEDES BENZ DEALER. 4TH ISSUE THE TRIANGLE LIGHT LOCATED IN THE CENTER OF DASH FLASHES OCCASIONALLY CAUSING UNDER CERTAIN CIRCUMSTANCES, TAPPING THE BRAKE PEDAL MAY NOT AUTOMATICALLY DISENGAGE CRUISE CONTROL AS EXPECTED IN CERTAIN MODEL YEAR RECALL SUBJECT: SUSPENSION: FRONT CONTROL ARM UPPER ARM .RECALL: 6/SERVICE BULLETINS: 2
I WAS DRIVING ON A BUSY INTERSECTION IN MY 2002 MERCEDES BENZ ML320 WHEN DRIVING THE YELLOW TRIANGLE IN THE SPEEDOMETER STARTS TO FLASH AND ALL THE BREAKS LOCK UP, THIS IS FOLLOWED BY A STALL, THANKFULLY I WAS ABLE TO PULL OFF TO THE SIDE OF THE ROAD WITHOUT BEING HIT. AFTER DOING SOME RESEARCH I DISCOVERED THAT MANY MERCEDES ML…
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I WAS DRIVING ON A BUSY INTERSECTION IN MY 2002 MERCEDES BENZ ML320 WHEN DRIVING THE YELLOW TRIANGLE IN THE SPEEDOMETER STARTS TO FLASH AND ALL THE BREAKS LOCK UP, THIS IS FOLLOWED BY A STALL, THANKFULLY I WAS ABLE TO PULL OFF TO THE SIDE OF THE ROAD WITHOUT BEING HIT. AFTER DOING SOME RESEARCH I DISCOVERED THAT MANY MERCEDES ML320 OWNERS WERE HAVING THIS SAME PROBLEM. SPECIFICALLY THE YAW RATE SENSOR. THIS IS A SERIOUS LIFE THREATENING ISSUE THAT CAN INJURE OR WORSE YET KILL SOMEONE. YOU GUYS NEED TO DO A RECALL BEFORE SOMEONE DIES!
TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT THE BAS AND ESP WARNING INDICATORS ILLUMINATED. IN ADDITION, THE CONTACT EXPERIENCED EXTREME DIFFICULTY TURNING LEFT AND RIGHT AND HAD TO RESTART THE VEHICLE SEVERAL TIMES DUE TO THE FAILURES. THE UNKNOWN DEALER WAS NOTIFIED OF THE FAILURE. THE MANUFACTURER…
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TL* THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT STATED THAT THE BAS AND ESP WARNING INDICATORS ILLUMINATED. IN ADDITION, THE CONTACT EXPERIENCED EXTREME DIFFICULTY TURNING LEFT AND RIGHT AND HAD TO RESTART THE VEHICLE SEVERAL TIMES DUE TO THE FAILURES. THE UNKNOWN DEALER WAS NOTIFIED OF THE FAILURE. THE MANUFACTURER WAS ALSO NOTIFIED. THE FAILURE MILEAGE WAS NOT AVAILABLE.
I HAVE A 2002 ML320, THE RADIO IS OUT AND THE HOLE CLAMP USED TO SECURE THE POWER STEERING FLUID DOES NOT PROVIDE SUFFICIENT CLAMPING CAUSING A LEAK, ESP/BAS STAYS ON CAUSING LOW TRACTION AND THE DOOR LOCK. THESE ITEMS WERE RECALLED ON THE M-CLASS 320, WHAT HAPPENED TO THES RECALLS.
TL* THE CONTACT OWNS A 2002 MERCEDES-BENZ ML320. WHILE DRIVING 10 MPH, THE VEHICLE FELT AS IF IT SLAMMED ON THE BRAKES WITHOUT THE CONTACT DEPRESSING THE BRAKE PEDAL. THE CONTACT STATED THAT THE EBS AND ABS WARNING LIGHTS REMAINED ILLUMINATED. THE CONTACT ALSO STATED THAT THE VEHICLE MADE A LOUD SCREECHING SOUND WHEN BEING DRIVE…
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TL* THE CONTACT OWNS A 2002 MERCEDES-BENZ ML320. WHILE DRIVING 10 MPH, THE VEHICLE FELT AS IF IT SLAMMED ON THE BRAKES WITHOUT THE CONTACT DEPRESSING THE BRAKE PEDAL. THE CONTACT STATED THAT THE EBS AND ABS WARNING LIGHTS REMAINED ILLUMINATED. THE CONTACT ALSO STATED THAT THE VEHICLE MADE A LOUD SCREECHING SOUND WHEN BEING DRIVEN. THE VEHICLE WAS TAKEN TO A LOCAL MECHANIC WHERE IT COULD NOT BE DIAGNOSED. THE MANUFACTURER WAS MADE AWARE OF THE FAILURE. THE FAILURE MILEAGE WAS APPROXIMATELY 175,000.
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
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
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
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
Official recalls
101V290000 · Suspension:front:control Arm:upper Arm
Sep 10, 2001
VEHICLE DESCRIPTION: PASSENGER VEHICLES. THE LEFT FRONT UPPER CONTROL ARM MAY NOT MEET THE SPECIFIED STRENGTH REQUIREMENTS.
Consequence & remedy
Consequence: THE CONTROL ARM COULD FAIL, INCREASING THE RISK OF A CRASH.
Remedy: DEALERS WILL REPLACE THE LEFT FRONT UPPER CONTROL ARM. OWNER NOTIFICATION BEGAN SEPTEMBER 29, 2001. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT MERCEDES-BENZ AT 1-800-367-6372.
Model-level recall history does not show whether a particular VIN is affected or has received a repair. Check a VIN with NHTSA ↗
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