Campaign - Brake Pressure Modulator Valve Malfunction: Overview
CUSTOMER SATISFACTIONBulletin No.: 10257B
Date: March 04, 2011
Subject: 10257B - Brake Pressure Modulator Valve Malfunction
Models:
2011 Buick LaCrosse
Attention:
SERVICE MANAGER & PARTS MANAGER: It is estimated that less than 20 vehicles world-wide will require replacement of the BPMV. Parts should only be ordered when inspection determines that it is necessary to replace the BPMV.
Supercede:
The Part Information section in this bulletin has been revised to instruct dealers to order the required module, if necessary, by contacting the Technical Assistance Center.Please discard all copies of bulletin 10257A, issued October 2010.
Condition
Certain 2011 model year Buick LaCrosse vehicles were built with a Brake Pressure Modulator Valve (BPMV) that contains a pressure relief valve that may not perform to GM specification under certain Antilock Braking (ABS) events. During normal braking and routine ABS events, the BPMV will perform as intended; however, a suspect pressure relief valve may not release a "locked wheel" during a "panic stop" type braking event until the driver begins to release the brake pedal. A vehicle with this condition will not see a degradation in stopping distance on dry pavement with a single-wheel lock up; however, the vehicle performance may not be as stable during heavy braking.
Correction
Dealers are to inspect and, if necessary, replace the BPMV.
Vehicles Involved
Involved are certain 2011 model year Buick LaCrosse vehicles built within these VIN breakpoints:
Important
Dealers are to confirm vehicle eligibility prior to beginning repairs by using the Required Field Actions section in the Global Warranty system. Not all vehicles within the above breakpoints may be involved.
For dealers with involved vehicles, a listing with involved vehicles containing the complete vehicle identification number, customer name, and address information has been prepared and will be provided to US and Canadian dealers through the GM GlobalConnect Recall Reports, or sent directly to export dealers. Dealers will not have a report available if they have no involved vehicles currently assigned.
The listing may contain customer names and addresses obtained from Motor Vehicle Registration Records. The use of such motor vehicle registration data for any purpose other than follow-up necessary to complete this program is a violation of law in several states/provinces/countries. Accordingly, you are urged to limit the use of this report to the follow-up necessary to complete this program.
Parts Information
Important
It is estimated that less than 20 vehicles world-wide will require replacement of the BPMV. Parts should only be ordered when inspection determines that it is necessary to replace the BPMV.
In the event that a module is required, dealers are to obtain the module by calling the Technical Assistance Center.
Service Procedure
ABS Wheel Lock-Up Inspection
Note
Perform the inspection below to determine if an electronic brake and traction control module with brake pressure modulator valve replacement is required. Two technicians and MDI and GDS are required to complete the inspection.
1. Lift and support the vehicle 305-610 mm (12-24 in) off of the ground. Refer to Lifting and Jacking the Vehicle in SI.
2. Connect MDI and GDS to vehicle.
3. Download Diagnostic Package GMNA Buick-Pontiac- GMC v2010. 9.1 (Sep 17, 2010).
1. From the Welcome to GDS screen select, Add New Diagnostic Package.
2. From the Update screen, select GMNA Buick-Pontiac- GMC v2010. 9.1 (Sep 17, 2010).
3. From the Login Page, select the install button below the Diagnostic Package Ready to Install menu.
4. After entering vehicle build information (e.g., vehicle identification number), select next action.
5. From the Diagnostics screen, navigate to Module Diagnosis>Electronic Brake Control Module>Control Functions. A pop-up menu will display that will require making a selection. The inquiry asks if the vehicle is equipped with a stability system. Select "Equipped"; do not select "Other" to reach the EBCM Control Functions menu.
6. Start the vehicle.
7. Move the gear selector into "N" neutral.
Note
One technician must be in the driver seat to apply brake pedal when requested in GDS tool. If possible, the technician in the vehicle should have the computer in the vehicle to read and follow the instructions provided in GDS. The technician outside of the vehicle should be performing the wheel inspections outlined in GDS.
Note
At the GDS Diagnostics screen, there is a question at the bottom of the screen inquiring if the wheel is blocked; this question should be "Is the wheel locked?".
8. Perform the four tests in the order presented in Control Functions. The four inspection tests proved below are listed in the correct order.
- CS-10257 ABS Left Front Solenoid Valves
- CS-10257 ABS Right Front Solenoid Valves
- CS-10257 ABS Left Rear Solenoid Valves
- CS-10257 ABS Right Rear Solenoid Valves
Note
When the GDS screen is prompted to "Depress and hold the brake pedal"; the inside technician will need to apply and hold heavy brake force. When sufficient pressure is achieved the GDS screen parameter "Brake Pressure Sensor Reached 80 bar" value changes from "Inactive" to "Active". Then the next "Yes" or "No" selection is available. This requested brake system level pressure (>80 bar) must be held constant during these GDS respective inspection tests; until prompted to release brake pedal.
1. To begin the inspection test, select the first inspection test: CS-10257 ABS Left Front Solenoid Valves. Carefully follow the on-screen instructions.
2. After completing the inspection test, note if the wheel passes or fails the inspection test. The wheel passes the inspection test if ALL of the answers to the questions are YES. If one or more of the questions receive a NO answer, the wheel does NOT pass the inspection test.
3. Move to the next inspection test: CS-10257 ABS Right Front Solenoid Valves. Carefully follow the on-screen instructions. Complete the inspection test and note if the wheel passes or fails the inspection test.
4. Move to the next inspection test: CS-10257 ABS Left Rear Solenoid Valves. Carefully follow the on-screen instructions. Complete the inspection test and note if the wheel passes or fails the inspection test.
5. Move to the last inspection test: CS-10257 ABS Right Rear Solenoid Valves. Carefully follow the on-screen instructions. Complete the inspection test and note if the wheel passes or fails the inspection test.
9. Determine if any of the wheels failed the inspection test.
- If all of the wheels passed the CS-10257 inspection test, lower the vehicle. Refer to Lifting and Jacking the Vehicle in SI. No further action is required.
- If one or more of the wheels failed the CS-10257 inspection test, lower the vehicle and replace the Electronic Brake and Traction Control Module with Brake Pressure Modulator Valve. Refer to Electronic Brake and Traction Control Module with Brake Pressure Modulator Valve Replacement in SI. Refer to Lifting and Jacking the Vehicle in SI.
Courtesy Transportation - For US and Canada
The General Motors Courtesy Transportation program is intended to minimize customer inconvenience when a vehicle requires a repair that is covered by the New Vehicle Limited Warranties. The availability of courtesy transportation to customers whose vehicles are within the warranty coverage period and involved in a product program is very important in maintaining customer satisfaction. Dealers are to ensure that these customers understand that shuttle service or some other form of courtesy transportation is available and will be provided at no charge. Dealers should refer to the General Motors Service Policies and Procedures Manual for Courtesy Transportation guidelines.
Warranty Transaction Information
Submit a claim using the table below.
Customer Notification - For US and Canada
General Motors will notify customers of this program on their vehicle (see copy of customer letter included with this bulletin).
Customer Notification - For Export
Letters will be sent to known owners of record located within areas covered by the US National Traffic and Motor Vehicle Safety Act. For owners outside these areas, dealers should notify customers using the attached sample letter.
Dealer Program Responsibility
All unsold new vehicles in dealers' possession and subject to this program must be held and inspected/repaired per the service procedure of this program bulletin before customers take possession of these vehicles.
Dealers are to service all vehicles subject to this program at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward.
Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the involved vehicle listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. A copy of the customer letter is provided in this bulletin for your use in contacting customers. Program follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter.
In summary, whenever a vehicle subject to this program enters your vehicle inventory, or is in your facility for service in the future, you must take the steps necessary to be sure the program correction has been made before selling or releasing the vehicle.
Disclaimer