NHTSA owner reports · September 18, 2026 snapshot.
Steering complaints
24 reportsClear category filter85,000 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
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
62,000 miles · Apr 7, 2009
SteeringInjury
I HAVE A 2002 MERCEDES BENZ (MB) ML320. THE POWER STEERING FLUID WAS DEPLETING ALL THE TIME FROM A LEAKAGE BETWEEN THE POWER STEERING PUMP AND THE HOSE. I TOOK THE VEHICLE TO AN MB DEALERSHIP IN GEORGETOWN, TX (GARLYN SHELTON MERCEDES BENZ DEALERSHIP). THE REPAIR WAS UNDER RECALL, BUT THE DEALERSHIP STILL CHARGED ME $214.16. I …
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I HAVE A 2002 MERCEDES BENZ (MB) ML320. THE POWER STEERING FLUID WAS DEPLETING ALL THE TIME FROM A LEAKAGE BETWEEN THE POWER STEERING PUMP AND THE HOSE. I TOOK THE VEHICLE TO AN MB DEALERSHIP IN GEORGETOWN, TX (GARLYN SHELTON MERCEDES BENZ DEALERSHIP). THE REPAIR WAS UNDER RECALL, BUT THE DEALERSHIP STILL CHARGED ME $214.16. I TOLD THEM THE REPAIR WAS FOR A RECALL, BUT THEY WOULD NOT LET ME TAKE MY CAR WITHOUT PAYMENT, SO I PAID THEM TO HAVE MY CAR BACK. HOWEVER, I'D LIKE NHTSA TO COMPEL THEM OR MERCEDES BENZ TO REFUND ME BACK MY $214.16. I WROTE TO MB HEADQUARTERS IN NEW JERSEY AND THEY SILL REFUSED TO REFUND ME BACK MY MONEY. I HAVE A RECEIPT OF THE REPAIR THAT WAS DONE ON THE CAR AND THE COST THEY BILLED ME. I CAN SEND YOU THE LETTER I WROTE TO MB HEADQUARTERS AND THE REPAIR RECEIPT IF YOU CONTACT ME. I'LL BE GRATEFUL IF YOU CAN HELP ME FROM THIS RIPOFF. *TR
NHTSA ODI #10264322
Mileage unknown · Feb 27, 2009
Steering
TL*THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. WHILE MAKING A TURN AT APPROXIMATELY 35 MPH, THE CONTACT HEARD A LOUD NOISE COMING FROM THE STEERING COLUMN. THE DRIVER HAD TO EXERT GREATER EFFORT TO MAKE A LEFT TURN. THERE WERE NO WARNING INDICATORS ILLUMINATED ON THE INSTRUMENT PANEL. ON SEVERAL OCCASIONS, THE VEHICLE WAS …
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TL*THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. WHILE MAKING A TURN AT APPROXIMATELY 35 MPH, THE CONTACT HEARD A LOUD NOISE COMING FROM THE STEERING COLUMN. THE DRIVER HAD TO EXERT GREATER EFFORT TO MAKE A LEFT TURN. THERE WERE NO WARNING INDICATORS ILLUMINATED ON THE INSTRUMENT PANEL. ON SEVERAL OCCASIONS, THE VEHICLE WAS TAKEN TO AN INDEPENDENT MECHANIC TO HAVE THE POWER STEERING FLUID RESERVOIR FILLED BECAUSE IT WAS EXTREMELY LOW. THE VEHICLE WAS TAKEN TO AN AUTHORIZED DEALER FOR DIAGNOSTIC TESTING AND THEY REPAIRED THE VEHICLE ACCORDING TO NHTSA CAMPAIGN ID NUMBER 03V-121. THE POWER STEERING COOLER HOSE AND ONE CLAMP WERE REPLACED; HOWEVER, THE FAILURE STILL PERSISTS. RECENTLY, THE FUEL PUMP HOSE AND CLAMPS WERE REPLACED AT THE CONTACT'S EXPENSE. THE TECHNICIAN RECOMMENDED THAT THE FUEL PUMP BE REPLACED. THE VIN AND MILEAGES WERE UNKNOWN.
NHTSA ODI #10260239
70,000 miles · Feb 12, 2009
Steering
TL*THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT RECEIVED A RECALL NOTICE AND TOOK THE VEHICLE TO THE DEALER FOR REPAIR. THE DEALER STATED THAT THE O-RING BETWEEN THE POWER STEERING PUMP AND RESERVOIR FAILED. AS A RESULT, THE RECALL REPAIRS WOULD BE INEFFECTIVE WITHOUT ALSO REPLACING THE O-RING. THE DEALER FURTHER…
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TL*THE CONTACT OWNS A 2002 MERCEDES BENZ ML320. THE CONTACT RECEIVED A RECALL NOTICE AND TOOK THE VEHICLE TO THE DEALER FOR REPAIR. THE DEALER STATED THAT THE O-RING BETWEEN THE POWER STEERING PUMP AND RESERVOIR FAILED. AS A RESULT, THE RECALL REPAIRS WOULD BE INEFFECTIVE WITHOUT ALSO REPLACING THE O-RING. THE DEALER FURTHER STATED THAT THE O-RING WOULD NOT BE COVERED BY THE RECALL; THEREFORE, THE CONTACT WOULD HAVE TO PAY AN ESTIMATED COST OF $162 FOR THIS REPAIR. THE NHTSA CAMPAIGN ID NUMBER WAS UNKNOWN. THE FAILURE AND CURRENT MILEAGES WERE LESS THAN 70,000. UPDATED 03/23/09. *LJ UPDATED 03/23/09. *JB
NHTSA ODI #10258519
113,000 miles · Sep 26, 2008
Steering
ON WEDNESDAY, SEPTEMBER 24, 2008, WHILE DRIVING TO WORK MY STEERING WHEEL BECAME DIFFICULT TO TURN. WHEN I LEFT WORK, I NOTICED THAT MOST OF THE STEERING FLUID HAD LEAKED OUT OF MY VEHICLE. THEN ON THURSDAY, A CO WORKER CONTACTED ME AND TOLD ME THAT SHE SAW A RECALL ON THE NEWS ABOUT THE STEERING ON MERCEDES SUV. I IMMEDIATELY C…
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ON WEDNESDAY, SEPTEMBER 24, 2008, WHILE DRIVING TO WORK MY STEERING WHEEL BECAME DIFFICULT TO TURN. WHEN I LEFT WORK, I NOTICED THAT MOST OF THE STEERING FLUID HAD LEAKED OUT OF MY VEHICLE. THEN ON THURSDAY, A CO WORKER CONTACTED ME AND TOLD ME THAT SHE SAW A RECALL ON THE NEWS ABOUT THE STEERING ON MERCEDES SUV. I IMMEDIATELY CONTACTED THE LOCAL DEALER AND WAS TOLD THAT THEY DID NOT HAVE A RECALL IN THEIR SYSTEM FOR MY AUTO AND IT WOULD COST ME $110 TO HAVE THEM DIAGNOSIS MY VEHICLE. I CONTACTED THE 800# THAT WAS ON THE NEWS AND WAS TOLD THAT SOMEONE WILL GET BACK WITH ME. IN THE MEANTIME, I AM A RECENT SINGLE PARENT WITH A 14 YEAR CHILD THAT I TRANSPORT IN A VEHICLE THAT I HAVING A DIFFICULT TIME TO STEER. *TR
NHTSA ODI #10243493
64,141 miles · Jan 25, 2008
Steering
LOWER POWER STEERING HOSE CLAMP HAD RELEASED AND ALLOWED THE POWER STEERING FLUID TO DISCHARGE TO THE GROUND. THIS LOSS OF FLUID DISABLED THE POWER STEERING RENDERING THE CAR ALMOST IMPOSSIBLE TO CONTROL WITHOUT STRONG STEERING INPUT. MY WIFE HAD TO CALL FOR ME TO DRIVE THE CAR HOME. THE HOSE FAILED UPON STARTUP, THUS PREVENTIN…
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LOWER POWER STEERING HOSE CLAMP HAD RELEASED AND ALLOWED THE POWER STEERING FLUID TO DISCHARGE TO THE GROUND. THIS LOSS OF FLUID DISABLED THE POWER STEERING RENDERING THE CAR ALMOST IMPOSSIBLE TO CONTROL WITHOUT STRONG STEERING INPUT. MY WIFE HAD TO CALL FOR ME TO DRIVE THE CAR HOME. THE HOSE FAILED UPON STARTUP, THUS PREVENTING AN ACCIDENT. THE UNIT WAS REPAIRED AT NO COST UNDER BULLETIN #T-B.46.30/13A. THIS BULLETIN EXTENDED THE WARRANTY TO 100,000 MILES FOR THIS PART. HOWEVER, THIS TYPE OF FAILURE MODE COULD RESULT IN LOSS OF CONTROL AND A CRASH. *TR
NHTSA ODI #10216023
71,000 miles · Nov 16, 2007
Steering
POWER STEERING PUMP IS DEFECTIVE IN THE 2002 ML 320. *TR
NHTSA ODI #10209174
Mileage unknown · Sep 14, 2005
Electrical SystemExterior LightingInterior Lighting
NUMEROUS PROBLEMS WITH EXTERIOR AND INTERIOR LIGHTING. MOST IMPORTANTLY THE LEFT TURN SIGNAL CONTINUALLY GOES OUT WITHOUT NOTICE. SOMETIME THE INTERIOR LEFT TURN LIGHTS UP AND SOMETIMES IT DOESN'T. OTHER TIMES THE INTERIOR LEFT TURN LIGHT GOES COMPLETELY OUT PLACING ME AND MY CHILDREN IN GREAT DANGER. ALSO I MADE A LEFT TURN…
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NUMEROUS PROBLEMS WITH EXTERIOR AND INTERIOR LIGHTING. MOST IMPORTANTLY THE LEFT TURN SIGNAL CONTINUALLY GOES OUT WITHOUT NOTICE. SOMETIME THE INTERIOR LEFT TURN LIGHTS UP AND SOMETIMES IT DOESN'T. OTHER TIMES THE INTERIOR LEFT TURN LIGHT GOES COMPLETELY OUT PLACING ME AND MY CHILDREN IN GREAT DANGER. ALSO I MADE A LEFT TURN AND THE STEERING WENT OUT JUST AS I ENTERED THE BELTWAY AND WAS UNABLE STEER THE VEHICLE. *NM
NHTSA ODI #10136498
Mileage unknown · Dec 1, 2003
Steering
THE POWER STEERING ON THE ML320 DOES NOT ALWAYS RESPOND TO ABRUPT CHANGES OF DIRECTION IN LOW SPEED MANEUVERS. ON NUMEROUS OCCASIONS, I HAVE STEERED TO THE LEFT OR RIGHT AT LOW SPEED (<10MPH) AND THEN QUICKLY TRIED TO STEER IN THE OPPOSITE DIRECTION. THE POWER STEERING REQUIRES A GREAT DEAL OF FORCE TO CHANGE THE INITIAL STEER D…
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THE POWER STEERING ON THE ML320 DOES NOT ALWAYS RESPOND TO ABRUPT CHANGES OF DIRECTION IN LOW SPEED MANEUVERS. ON NUMEROUS OCCASIONS, I HAVE STEERED TO THE LEFT OR RIGHT AT LOW SPEED (<10MPH) AND THEN QUICKLY TRIED TO STEER IN THE OPPOSITE DIRECTION. THE POWER STEERING REQUIRES A GREAT DEAL OF FORCE TO CHANGE THE INITIAL STEER DIRECTION AND IT IS EXTREMELY DIFFICULT TO CHANGE DIRECTION. THIS COULD EASILY RESULT IN AN ACCIDENT. I DON'T BELIEVE THIS BEHAVIOUR IS UNIQUE TO MY PARTICULAR VEHICLE BUT IS INSTEAD A COMMON TRAIT OF ALL MLS.*AK
NHTSA ODI #10048971
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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