NHTSA Office of Defects Investigation
Preliminary Evaluation PE08-016: INADEQUATE BRAKE POWER ASSIST
- Closed
NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE08-016 on March 6, 2008 and closed it on June 24, 2008. NHTSA's investigations file lists the Pontiac Solstice and Saturn Sky for it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- PE08-016 (also written PE08016)
- Investigation type
- Preliminary Evaluation The first stage of most defect investigations: NHTSA's Office of Defects Investigation gathers basic information about a possible safety defect, including from the manufacturer.
- Status
- Closed June 24, 2008
- Opened
- Closed
- Vehicle or equipment manufacturer
- General Motors, LLC
- Components
- Service Brakes, Hydraulic; Service Brakes, Hydraulic — Antilock/Traction Control/Electronic Limited Slip; Service Brakes, Hydraulic — Antilock/Traction Control/Electronic Limited Slip — Control Unit/Module; Service Brakes, Hydraulic — Power Assist; Service Brakes, Hydraulic — Power Assist — Hydraulic; Service Brakes, Hydraulic — Power Assist — Vacuum
- Vehicles and equipment
- Pontiac Solstice and Saturn Sky
A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.
NHTSA's summary
As NHTSA's Office of Defects Investigation wrote it for Preliminary Evaluation PE08-016.
IN MODEL YEAR (MY) 2007, PONTIAC SOLSTICE AND SATURN SKY VEHICLES EQUIPPED WITH THE 2.0L TURBOCHARGED ENGINE USED AN AUXILIARY VACUUM PUMP TO SUPPLEMENT THE ENGINE AS A SOURCE OF VACUUM TO THE BRAKE BOOSTER DURING LOW VACUUM CONDITIONS, SUCH AS IMMEDIATELY AFTER A COLD START.THE VACUUM PUMP OPERATION WAS CONTROLLED BY SWITCHES THAT SENSED BOOSTER VACUUM, TURNING THE PUMP ON WHEN BOOSTER VACUUM DROPPED BELOW A SPECIFIED LEVEL.IN THE MY 2008 SOLSTICE AND SKY VEHICLES (THE SUBJECT VEHICLES), GENERAL MOTORS (GM) ELIMINATED THE AUXILIARY VACUUM PUMP AND REPLACED IT WITH THE OPTIMIZED HYDRAULIC BRAKING (OHB) SYSTEM.THE DESIGN INTENT OF OHB IS TO SUPPLEMENT ENGINE VACUUM, IN CONDITIONS WHERE LOW VACUUM IS GENERATED BY THE ENGINE, WITH HYDRAULIC PRESSURE GENERATED BY THE STABILITY CONTROL SYSTEM PUMP CONTROLLED BY THE ELECTRONIC BRAKE CONTROL MODULE (EBCM). FOR UP TO ABOUT AMINUTE AFTER A COLD START, WHEN THE SYSTEM IS IN OHB ASSIST MODE, THE DRIVER MUST PRESS HARDER ON THE BRAKE PEDAL TO ACHIEVE DESIRED DECELERATION.ALSO, WHEN THE OHB MODE IS ACTIVATED, THE DRIVER CAN HEAR AND FEEL, THROUGH BRAKE PEDAL VIBRATION, THE STABILITY CONTROL SYSTEM PUMP OPERATION.STARTING IN LATE APRIL 2008, GM CHANGED FROM THE OHB SYSTEM BACK TO THE VACUUM PUMP SYSTEM DESIGN.ODI IS AWARE OF 264 NON-DUPLICATIVE COMPLAINTS TO ODI AND GM ALLEGING INADEQUATE BRAKE POWER ASSIST IN THE SUBJECT VEHICLES WHEN APPLYING THE BRAKES JUST AFTER A COLD START, INCLUDING ONE INCIDENT INVOLVING A CRASH INTO A TREE DURING A DRIVEWAY MANEUVER.TO ADDRESS THESE CONCERNS BY CONSUMERS, GM HAS ISSUED THREETECHNICAL SERVICE BULLETINS.ON JUNE 4, 2007, GM RELEASED AN INFORMATIONAL BULLETIN (NO PART REPLACEMENT OR SOFTWARE UPDATES), BULLETIN# 07-05-22-002, TO DEALERS EXPLAINING THE FUNCTIONALITY OF THE OHB SYSTEM.ON NOVEMBER 29, 2007, GM RELEASED A SERVICE BULLETIN, BULLETIN# 07-05-22-007, WITH INSTRUCTIONS TO RECALIBRATE THE EBCM WITH REVISED SOFTWARE TO MAKE OHB OPERATION FEEL MORE LIKE A NORMAL VACUUM ASSIST SYSTEM.TO IMPROVE COLD START BRAKING PERFORMANCE COMPARABLE TO MY 2007 VEHICLES, GM RELEASED A THIRD SERVICE BULLETIN IN TWO PARTS, BULLETINS 07-05-25-007A (APRIL 29, 2008) AND 07-05-25-007B (MAY 16, 2008), FOR AUTOMATIC AND MANUAL TRANSMISSION VEHICLES RESPECTIVELY.THESE BULLETINS RELEASED NEW ENGINE CONTROL SOFTWARE TO CHANGE THE IDLE STRATEGY AFTER A COLD START SO THAT MORE VACUUM IS AVAILABLE FOR BRAKE POWER ASSIST.BEGINNING THE WEEK OF JUNE 23, 2008, GM WILL BEGIN SENDING LETTERS TO CONSUMERS TO MAKE THEM AWARE OF THE AVAILABILITY OF MOST RECENT CALIBRATION.A SAFETY-RELATED DEFECT HAS NOT BEEN IDENTIFIED AT THIS TIME AND FURTHER USE OF AGENCY RESOURCES DOES NOT APPEAR TO BE WARRANTED.ACCORDINGLY, THIS INVESTIGATION IS CLOSED.THE CLOSING OF THIS INVESTIGATION DOES NOT CONSTITUTE A FINDING BY NHTSA THAT A SAFETY-RELATED DEFECT DOES NOT EXIST.THE AGENCY WILL TAKE FURTHER ACTION IF WARRANTED BY THE CIRCUMSTANCES.
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE08-016. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.
Pontiac
Pontiac Solstice
Saturn
Saturn Sky
What an NHTSA investigation is
NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.
An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.
To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.
Free VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for PE08-016
Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.