Investigations
| NHTSA ID | Manufacturer | Date open | Date close | Subject | Recall campaign | |
|---|---|---|---|---|---|---|
| SERVICE BRAKES, HYDRAULIC | ||||||
| PE10050 | MERCEDES-BENZ USA, LLC. | 12/21/2010 | 05/04/2011 | Brake lamp switch failure. | 11V208000 | |
| 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 to consumers in september 2011.this action taken by mb is sufficient to resolve the issues raised by this investigation. | ||||||
| SERVICE BRAKES, HYDRAULIC - FOUNDATION COMPONENTS - HOSES, LINES/PIPING, AND FITTINGS | ||||||
| EA08009 | MERCEDES-BENZ USA, LLC. | 04/28/2008 | 12/16/2009 | BRAKE LINE CHAFE | ||
| Analysis of complaints to odi and mercedes and warranty claim data submitted by mercedes indicates that the alleged defect has occurred at a low rate (36.5 complaints per 100,000 vehicles and 0.29 percent warranty claim rate), with no discernable defect trend indicating that the rate of chafing related brake line failures is increasing.there have been no new complaints since january 2009.when the analysis is limited to incidents of brake line leakage that resulted in allegations of reduced brake effectiveness, the rate drops even further (22.3 complaints per 100,000 vehicles and 0.04 percent warranty claim rate). mercedes provided data showing that in the rare instances when chafing did progress to brake line leakage the driver would be immediately alerted to a problem by illumination of the bright yellow esp/bas warning lamp and changes in brake pedal feel.continued operation with a leaking brake line would result in illumination of the bright red brake warning lamp and an audible chime due to low master cylinder reservoir level. continued operation with the brake warning lamp illuminated would ultimately drain the reservoir for the affected circuit, resulting in loss of the circuit and an approximately 80% increase in stopping distances. surveys conducted by odi and vrtc indicate that routing anomalies may be more common than the complaint and warranty data suggest for the subject line bundle, with line contact or other routing anomaly noted in 13 of 51 vehicles surveyed by odi and vrtc (25.5%).while evidence of contact between the fuel line and subject brake in a particular vehicle is not necessarily predictive of eventual line failure/leakage, significant chafing wear was noted in two survey vehicles (3.9%).to address concerns with line routing and ensure that lines with evident chafing do not progress to a leak condition, mercedes will conduct an owner notification program instructing owners to bring the vehicles to a dealer for a free inspection and repair.lines that do not have a spacer (rubber grommet or omega-clip) between the subject fuel and brake lines will have an omega-clip spacer installed to ensure adequate clearance between the lines.brake lines with chafe marks will be replaced. accordingly, this investigation has been closed. the closing of this investigation does not constitute a finding by nhtsa that a safety-related defect does not exist. the agency will continue to monitor complaints and other information relating to the alleged defect in the subject vehicles and take further action in the future if warranted. for additional information regarding this engineering analysis refer to the ea08-009 closing report. | ||||||
| SERVICE BRAKES, HYDRAULIC - SWITCHES - BRAKE LIGHT | ||||||
| PE10050 | MERCEDES-BENZ USA, LLC. | 12/21/2010 | 05/04/2011 | Brake lamp switch failure. | 11V208000 | |
| 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 to consumers in september 2011.this action taken by mb is sufficient to resolve the issues raised by this investigation. | ||||||
| PE10050 | MERCEDES-BENZ USA, LLC. | 12/21/2010 | Brake Lamp Switch Failure | |||
| Odi has received 15 vehicle owner questionnaire reports that allege that the brake lamp switch failed resulting in one or more of the following conditions: loss of illumination of the exterior brake lamps, an inability to shift the vehicle out of park gear position, and/or an inability to disengage the cruise control system once enabled and set.mercedes benz has previously issued technical service bulletin (tsb) 10016685, dated may 16, 2005, which discusses an improved and/or revised brake lamp switch service replacement part.odi is opening this pe to further evaluate this issue. | ||||||
Consumer Complaints
| Fail date | miles | occurences | Purchase date |
|---|---|---|---|
| SERVICE BRAKES, ELECTRIC | |||
| 11/19/2009 | 120000 | 1 | |
| The antilock braking system can take over throttle and braking. vehicle will automatically apply brakes to various wheels. it will pitch the car left or right and require driver to counter steer to keep the vehicle straight. there is no warning on when this will happen. can cause accident or cause vehicle to spin. mercedes dealer service manager advise me it is a faulty sensor and it is replace at owners expense for $600. i complaint that it is dangerous and should be replaced. service advisor simply replied yes it is, you should pay for the repair. *tr | |||
| SERVICE BRAKES, HYDRAULIC | |||
| 11/03/2009 | 87000 | 1 | |
| 2000 ml-class mercedes ml55 leaking brake line due to chaffing as described in your investigation of 52,000 ml-class mercedes suv's. the brake line running from the master cylinder to the abs pump suffers eventual failure due to chaffing against a poorly positioned fuel line. suffered near total failure of braking system this morning due to this issue. i have all parts removed, and a failure assessment provided by the service technician. the work was not performed at a mercedes benz dealer, thereby ensuring objectivity of the diagnosis. *tr | |||
| 08/15/2007 | 57000 | 1 | 02/10/2002 |
| My biggest concern with the ml320 that i have owned since 2002, but not the only concern would be the braking system. i complained from a couple of months into buying this vehicle that i did not feel safe. the vehicle brakes goes into a locked position if you drive over a bump, man hole, or if it rains the suv skids as if you are losing control of the vehicle. the bas esp light comes on often, which warns you that the braking system is not working properly, it is on as i am complaining now. i have taking it to the dealership on more than one occasion complained over the phone with this issue and many more. the dealership replace a switch i believe maybe in 20002. the eps have come on even after that. i am very fearful when it comes the braking especially in rain or ice. i have had so many issues with this vehicle, i will not recommend it to anyone. this vehicle has been a nightmare! mercedes benz would not purchase vehicle back but offer to make things right with repairs. *jb(... yes the brakes lock whenever you press the brakes, almost skid without stopping vechicle...especially scary in rain or running over a manhole cover. it very weird.....braking system light come on often bas light)*smch | |||
| SERVICE BRAKES, HYDRAULIC - ANTILOCK - CONTROL UNIT/MODULE | |||
| 11/11/2005 | 37648 | 3 | 08/02/2000 |
| Bas/esp light comes on, brakes engage, steering wheel turns to the right...happens at speeds 60 mph and higher; car difficult to control, no warning--i have used two category options on the form, but i really do not know which options to choose to describe the above problem...suv has done this on expressway driving over and over for the past 6 years....each time the dealer thinks they have fixed the problem....*nm | |||
| SERVICE BRAKES, HYDRAULIC - FOUNDATION COMPONENTS - HOSES, LINES/PIPING, AND FITTINGS | |||
| 02/08/2009 | 66335 | ||
| Without any warning, when coming to a traffic stop the brake pedal on my 2000 mercedes ml55 went to the floor. i was able to stop after reapplying the brake and pushing very hard. fortunately no cars were in front of me or i would have hit them. i pulled to the side of the street and looked under the hood, noticed the brake fluid was low, put some fluid in and drove a short distance to work. the brakes were very soft. the next day took the vehicle to my mercedes dealer where they found that a brake line was rubbed through and leaking. no indicator lights or warnings of any kind occurred before the problem. | |||