Solstice L4-2.0L Turbo (2008)
Hydraulic Brake Booster: Technical Service Bulletins
Brakes - Optimized Hydraulic Boost Characteristics
Bulletin No.: 07-05-22-002
Date: June 04, 2007
INFORMATION
Subject:
Information on Optimized Hydraulic Boost Characteristics
Models:
2008 Pontiac Solstice GXP
2008 Saturn Sky Redline
2008 Opel GT
with 2.0L Engine (VIN X - RPO LNF)
The Optimized Hydraulic Boost (OHB) is a standard feature, included with all 2008 vehicles equipped with the 2.0L (RPO LNF) engine). OHB assists
brake operation under low engine vacuum conditions using the ABS system.
If your vehicle has Electronic Stability Control (ESC) and the 2.0L turbocharged engine, it will also have a hydraulic brake boost feature which
supplements the power brake system to maintain consistent brake performance under conditions of low brake booster vacuum utilizing the ABS system.
Increased brake pedal effort due to low brake booster vacuum conditions may exist during;
^
The initial cold engine start up and the first few brake applies.
^
When the vehicle has been parked for extended periods and/or at higher altitudes and restarted.
^
Any time the vehicle is started up after a brake booster has been completely bled down (no stored vacuum).
The OHB functions are controlled by the Electronic Stability Control (ESC) Module. The ESC module determines when to activate the OHB.
The following OHB characteristics are considered to be normal:
Increased brake pedal effort under low brake booster vacuum.
Change in brake pedal effort when OHB is active.
Ratchet sound coming from the brake system during OHB activation.
Frequent brake stops may result in OHB activation.
High altitude driving may result in OHB activation.
Brake pedal movement or pulsation when the OHB is active.
Some customers may bring their vehicle back to the dealership commenting on any or all of the above characteristics. The customer may experience
brake pedal movement or pulsation accompanied by a change in brake pedal effort when the OHB is active.
Do not attempt to repair or replace any parts for what is considered normal operation of the OHB.
If a condition should exist in which you might not be receiving the intended brake boost, the SVC BRAKE SYSTEM message may be displayed on the
DIC.
Disclaimer
